General

AR-15 Custom Build Guide – 2017 Edition

I’ve written my advice for first time buyers of AR-15’s before, and provided plenty of technical details for barrels, optics, triggers, and other topics. However, I’ve never put together a list of suggested parts for a ground-up build. To be honest, that was intentional.

My general advice for new buyers was, and continues to be, go out and buy something like a Colt OEM for less than $800 and make it yours. Even better, pick up a complete Colt 6720 right now for $899 and rock on.

Still, I get a lot of questions about assembling rifles from scratch and picking parts.
This guide is my answer. This post is only concerned about the rifle itself, and not optics or sights. I break it down into functional categories and budget lines. You will see that I tend to stick to a baseline build, and then change only a few parts as the budget goes up.

This guide is based upon what is available right now. I know there are plenty of cool new whiz bangs just over the horizon (I’m looking at you UBR 2.0), but that makes things too complicated. Maybe they’ll make it in the guide next year. Also, I am not including the cost of shipping, tools, or paying someone to do the assembly for you. This is purely based on the cost of the parts.

I’m sure there are people who would read this list and wouldn’t agree with me. That’s fine. This is ultimately what I would build for myself were I to start all over again and choose to go the parts-rifle path. What works for me doesn’t work for everyone. Some of the decisions I made were driven by the budget I constrained myself to. Other decisions were honestly a wash between different parts, so I just picked one that met my needs.

The General-Purpose Carbine


The general-purpose carbine (GPC) is for someone who needs “the one rifle.” It is fairly good at most things, while not being outstanding at anything. It is easy to carry, easy to shoot, accurate enough, and serves as a constant companion for everything from home defense to competition. For most people, this is the category they are looking for when it comes to a “SHTF” gun.

The Baseline

Price Point: $800-$1000

The baseline GPC consists of the bare bones components needed to get a reliably functioning weapon. The parts on the baseline are inexpensive, without being “cheap,” and still theoretically meet reliability standards. I say theoretically because when go for a parts-rifle frankengun assembled from different brands, there is just never a guarantee.

This a great first rifle for someone who is ignoring advice to just buy factory built uppers and lowers, as it allows plenty of room for expansion in the future.

Contrary to my own advice, I went with a free floated barrel and low profile gas block from the start. I probably could have saved some money by going with standard handguard furniture and triangle front sight on the front end, but the labor costs would be higher on assembly due to the required drilling and pinning. Those labor costs would negate any savings made on going with standard plastic hardware, so I just skipped it.

Estimated weight: 6.37 lbs 
Estimated Cost: $894.39

Lower Receiver:

  • Stripped lower from Aero Precision
  • Daniel Defense LPK
  • Basic mil-spec trigger (included in the lower parts kit)
  • A2 pistol grip (included in LPK)
  • Standard safety selector (included in LPK)
  • Magpul MOE trigger guard (included in LPK)
  • BCM buffer tube
  • BCM carbine spring
  • H2 buffer
  • Magpul MOE carbine stock

Upper Receiver:

  • Aero Precision assembled flat top upper
  • 16” Faxon Gunner barrel
  • Faxon low-profile gas block
  • Standard mid-length gas tube
  • A2 “birdcage” flash hider and crush wafer
  • Aero Precision BCG
  • ALG EMR V3 13″ M-Lok handguard (and barrel nut)
  • BCM Mod4 charging handle

The Custom

Price Point: $1000-$1500

At the “custom” level, we can add a few more options that improve the shooting characteristics of the rifle. Changes from the baseline to the custom category include a Criterion barrel, known for high accuracy with chrome lining, a Centurion Arms handguard, A5 buffer kit, and a two-stage trigger (among other components). I also switched to a BCM M4 upper receiver because they are known for tight machining tolerances, particularly around the barrel extension, and help contribute to accuracy. The change from an Aero BCG to a BCM BCG came about mostly because I trust BCMs QC methods, as they individually test every bolt.

Estimated weight: 6.28 lbs
Estimated cost: $1303.17

Lower:

  • Aero Precision stripped lower
  • BCM Intermediate Buffer Tube (A5 Compatible)
  • Mil-Spec rifle buffer spring
  • Vltor A5H0 buffer
  • Sionics “Builder” lower parts kit (minus ambi safety selector)
  • V Seven Short throw safety selector
  • Larue MBT Trigger
  • BCM Gunfighter Stock
  • Hogue Overmold pistol grip (without grooves)

Upper:

  • BCM M4 flat top upper receiver (assembled)
  • Criterion 16” light hybrid barrel, sold through Midwest Industries
  • Faxon low profile gas block
  • Standard mid-length gas tube
  • Centurion Arms CMR M-Lok handguard (and barrel nut)
  • BCM M-16 Bolt Carrier
  • BCM Mod4 charging handle
  • A2 flash hider

The Unlimited

Price Point $1500-$2000

At the “Unlimited” level, we are looking to push the shooting characteristics of the gun to the best that can be expected of the general purpose carbine category. If funds are unlimited, and local politics allow, this is a great point to dip into NFA territory with suppressors and 14.5” barrels. For now, though, I will stay away from that and keep to keeping it NFA-friendly territory.

The goal is to continue pushing for more durable and accurate components while keeping weight down. With the unlimited category, I brought in matched billet receivers from CMT. These include several innovative ambidextrous features for magazine release and bolt stop. I switched to a Centurion Arms barrel, which is made from a different blend of steel, and known for both good accuracy and great durability. For the rail, I moved to a BAD 13.7″ Rigidrail, due to its very light weight while keeping rigidity. For a trigger, I brought in a Geissele SD-C. To be honest, my Larue MBT and Geissele SD-E are so close that another trigger upgrade is optional here.

To be honest, I had trouble pushing the budget much past the $1700 point. I could have spent another couple hundred on a lightweight billet set from Battle Arms Development or 2A Armament, but neither of them have the ambidextrous features that I think are valuable in this style of weapon. I could have also switched stocks to something more expensive, but at what point am I just picking more expensive parts for the sake of spending more money?

Estimated Weight: 6.54 lbs
Estimated Cost: $1897.13

Lower Receiver:

  • CMT Tactical Billet Ambi
  • BCM Intermediate Buffer Tube (A5 Compatible)
  • Sprinco ‘Green’ buffer spring
  • Vltor A5H0 buffer
  • Sionics “Builder” lower parts kit (minus ambi safety selector)
  • V Seven Short throw safety selector
  • Geissele SD-C trigger
  • BCM Gunfighter Stock
  • Hogue Overmold pistol grip (without grooves)

Upper Receiver:

  • CMT Billet receiver
  • Centurion Arms 16″ CHF lightweight
  • Centurion pinned low profile gas block
  • Standard mid-length gas tube
  • V Seven 13.5″ Enlightened M-Lok handguard (with barrel nut)
  • BCM M-16 Bolt Carrier
  • Geissele ambi charging handle
  • Precision Armament AFAB compensator (and shim kit)

The Field Rifle


The field rifle is one that will be carried mainly in open outdoors. It is at home slung across your back as you climb over rocky terrain, or slung up while lining up for a shot on a coyote. It is light and balanced, with a minimum of fuss. It can be pushed into service for defense of the home, but it is longer than a carbine built for the purpose. While not at the highest level of precision, it is more accurate than most shooters and will work well on all but the smallest targets out to the practical limits of the 5.56 cartridge.

My priorities for a field rifle are stability, balance, and velocity. Since this rifle is not intended for indoors or vehicle use, it is longer. It may be slightly heavier, but the weight is balanced to offset it. I’ll stick with the Magpul MOE rifle stock for all three levels because it is rigid, provides good cheek weld, and makes for a great overall feel on a field rifle. Your mileage, of course, may vary.

The Baseline

Price Point: $800-$1000

At the baseline, the field rifle looks similar to the GPC, except that it is slightly longer to take advantage of added velocity. Keeping to a budget will force decisions like that. The primary goal is to remain lightweight and easy to carry, but feel more substantial and confidence-inspiring in the hand. This will come mainly through paying attention to how the rifle balances.

Estimated Weight: 6.62 lbs
Estimated Cost: $969.32

Lower Receiver:

  • Stripped lower from Aero Precision
  • BCM Enhanced LPK
  • BCM PNT (included in the lower parts kit)
  • BCM pistol grip (included in LPK)
  • Standard safety selector (included in LPK)
  • Magpul MOE trigger guard (included in LPK)
  • BCM rifle buffer tube
  • Standard rifle buffer spring
  • Standard rifle buffer
  • Magpul MOE rifle stock

Upper Receiver:

  • Aero Precision assembled flat top upper without forward assist
  • 18” Faxon Gunner barrel
  • Faxon low-profile gas block
  • Standard rifle-length gas tube
  • BCM Gunfighter Mod 0 compensator
  • Aero Precision BCG
  • ALG EMR V3 15″ M-Lok handguard (and barrel nut)
  • BCM Mod4 charging handle

The Custom

Price Point: $1000 – $1500

With some extra funds, we can increase the accuracy and balance characteristics of the rifle. I happen to prefer a slight forward balance on a field rifle, since it helps the rifle settle into my hand and reduce sway from field positions. As with the general purpose carbine, I will make some adjustments to parts choices for the sake of tolerances and accuracy. The biggest adjustments will come from the barrel and trigger.

Estimated Weight: 7.2 lbs
Estimated Cost: $1377.72

Lower Receiver:

  • Stripped lower from Aero Precision
  • Sionics “Builder” LPK
  • Larue MBT Trigger
  • BCM pistol grip
  • V Seven short throw safety
  • Magpul MOE trigger guard
  • BCM rifle buffer tube
  • Standard rifle buffer spring
  • Standard rifle buffer
  • Magpul MOE rifle stock

Upper Receiver:

  • Rainier Arms non-forward assist upper
  • 17.7″ Ballistic Advantage Hanson profile 3-gun barrel
  • Ballistic Advantage pinned gas block (included with barrel)
  • Standard mid-length gas tube
  • BCM Gunfighter Mod 0 compensator
  • BCM BCG
  • Mega Arms Wedge-Lock M-Lok handguard (and barrel nut)
  • BCM Mod4 charging handle

The Unlimited

Price Point: $1500 – $2000

At the top end, we can take advantage of billet receivers and other higher end items. Overall, though, it retains the same basic style.

Estimated Weight: 7.4 lbs
Estimated Cost: $1905.80

Lower Receiver:

  • 2A Armament Balios Lite
  • Sionics “Builder” LPK
  • Geissele SD-E Trigger
  • BCM pistol grip
  • V Seven short throw safety
  • BCM rifle buffer tube
  • Standard rifle buffer spring
  • Standard rifle buffer
  • Magpul MOE rifle stock

Upper Receiver:

  • 2A Armament Balios Lite
  • 18″ Criterion Hybrid Profile barrel
  • BCM Low Profile gas block
  • Standard rifle-length gas tube
  • Precision Armament AFAB Compensator
  • BCM BCG
  • Mega Arms Wedge-Lock M-Lok handguard (and barrel nut)
  • Geissele charging handle

The Precision Shooter


This rifle is all about precision. It is at home on a bipod or a sandbag. It is heavy, a bit unwieldy, and not meant to be carried for long periods. It is ideally used in competition, but would serve very well for varmint shooting off the back of a truck. At all three levels here, I will use a longer barrel for the flattened trajectory, which is more useful to me.

From a precision standpoint, a more compact 16″ barrel would work just as well. Precision costs money, so there is increased cost at all levels.

The Baseline

Price point: $800-$1000

My priorities for this category of rifle are precision and stability. I also like a smooth cycle that helps keep sights on target for better shot calling.

Estimated Weight: 8.2 lbs
Estimated Cost: $961.89

Lower Receiver:

  • Stripped lower from Aero Precision
  • BCM Enhanced LPK
  • BCM PNT (included in the lower parts kit)
  • BCM pistol grip (included in LPK)
  • Standard safety selector (included in LPK)
  • Magpul MOE trigger guard (included in LPK)
  • BCM rifle buffer tube
  • Standard rifle buffer spring
  • Standard rifle buffer
  • Magpul MOE rifle stock

Upper Receiver:

  • Aero Precision assembled flat top upper without forward assist
  • Ballistic Advantage 20″ DMR Premium Series
  • Rainier Arms low-profile gas block
  • Standard rifle-length gas tube
  • A2 flash hider
  • Aero Precision BCG
  • ALG EMR V3 15″ M-Lok handguard (and barrel nut)
  • BCM Mod4 charging handle

The Custom

Price point: $1000- $1500

At the custom level, not much will change with the core rifle. We get the addition of a better trigger, adjustable stock, rail, and muzzle device.

Estimated Weight: 7.8 lbs
Estimated Cost: $1414.77

Lower Receiver:

  • Stripped lower from Aero Precision
  • BCM Enhanced LPK
  • Larue MBT Trigger
  • BCM pistol grip (included in LPK)
  • Standard safety selector (included in LPK)
  • Magpul MOE trigger guard (included in LPK)
  • BCM intermediate buffer tube
  • Sprinco “green” rifle spring
  • A5 buffer
  • BCM Gunfigher Mod 0 stock

Upper Receiver:

  • Aero Precision assembled flat top upper without forward assist
  • Ballistic Advantage 20″ DMR Premium Series
  • Rainier Arms low-profile gas block
  • Standard rifle-length gas tube
  • BCM Compensator
  • Aero Precision BCG
  • Mega Wedge-Lock M-Lok handguard (and barrel nut)
  • BCM Mod4 charging handle

The Unlimited

Price point: $1500-$2000

The unlimited level will change out the receivers, barrel, and a few operating parts. I’m sure there will be great debate over why I chose the parts I did, particularly the barrel, when there are known better ones out there. The answer is budget. To keep this below the $2k mark, I had to make some sacrifices. The parts I picked will still perform very well while staying well below the extraordinary prices some folks are willing to pay in the precision game.

Remember, when it comes to precision, the rifle is less important than the optics you put on it and your own abilities.

Estimated Weight: 8 lbs
Estimated Cost: $1964.82

Lower Receiver:

  • Mega Arms Billet Lower
  • Sionics LPK
  • Geissele High-Speed DMR trigger
  • Hogue overmold grip without finger grooves
  • V Seven short throw safety
  • BCM intermediate buffer tube
  • Sprinco “Green” rifle spring
  • A5 buffer
  • BCM Gunfighter Mod 0 stock

Upper Receiver:

  • Mega Arms Billet Upper
  • Rainier Arms Ultramatch .223 Wylde 20″ barrel
  • Rainier Arms low-profile gas block
  • Standard rifle-length gas tube
  • Precision Armament AFAB compensator
  • Aero Precision BCG
  • Mega Arms Wedge Lock M-lok handguard (and barrel nut)
  • BCM Mod4 charging handle

Conclusion

This concludes my build sheets for this year. The AR-15 is an extremely versatile and popular platform. You can take any of the specs I laid out above and further tweak them, but I do think they give you a good solid base to start from with each category and price point.

Good luck!

General

Just One More Step on the New Rifle

mockup

This project is almost in the bag…or in the safe. Whatever.

I ordered the wrong size triangular hand guard cap by mistake. I didn’t check if the Colt one I purchased was for .750 or .625 barrels. I needed the latter, but ended up with the former. Not a big deal, since it’s a $3 part and already ordered the correct one from BCM.

Once I have that, the upper is off to West Coast Armory for pinning the FSB and final assembly.

I am very happy with the mock up pictured above. I assembled all the parts without final torquing, and it handles beautifully. Balance is right at the rear of the magazine well. The Rainier Arms upper and lower receivers have the tightest fit I’ve ever seen, and the whole thing just feels solid. I expect this may be a new favorite.

Not much longer until it’s off for a trip to the range.

General

New Rifle Update

IMG_0892.JPG

Not long ago, I mentioned having the urge to start a new project.  My observation back in June was that my main rifle, which began life as a KISS iron sight rifle, had grown in weight and capability to become my go-to for most things. Despite that, I still really enjoyed the basic configuration. I started sketching out a new lightweight minimalist project, which I’m designating my “field rifle,” or “walking around rifle.”

This is the original mockup I did on Gunstruction.

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At this point, I have the lower assembly completed.

  • Rainier Arms lower receiver
  • Sionics lower parts kit
  • Magpul MOE Rifle Stock
  • Hogue overmold pistol grip without finger grooves
  • ALG ACT trigger
  • Magpul MOE trigger guard

IMG_0888.JPG

I’ve been playing with this assembled lower on my 20″ upper to see how I like it. So far, so good. The Rainier lower, which I presume is made by Mega Machine based on some of the features, is very nice. The roll pin holes were tight, which is not a bad thing, and took some finesse on my part. I’m not one to mind my lowers looking a little “used,” but I can see some people being concerned about the effort required to drive in certain pins (particularly the trigger guard).

The Hogue pistol grip is quite nice, it has the nice rubberized texture Hogue is famous for, a subtle palm swell, and is shaped more or less like an A1 grip. The Hogue grips have a little lip protrusion that is intended to fill the gap created by the standard AR trigger guard. However, since I’m using a Magpul MOE trigger guard, which is designed to fill the gap itself, I had to cut the “lip” off the top of the grip. No big deal, less than a minute with my Leatherman.

The MOE Rifle stock is awesome. I installed one on an unfinished 308 lower years ago, and have shot them on rifles I’ve built for friends, but never put one on one of my own ARs. It offers a very nice cheek weld and fits my length of pull perfectly.

The ACT trigger has been in my stable for years as a backup to my Geissele triggers. It will be front-and-center now, though. It’s just a good all-round mil spec style trigger. The single stage has a very minor amount of creep, but I don’t really care given the style of shooting this project is intended for.

Going forward, I plan on using a Faxon 18″ Gunner barrel (with a Criterion Ultralight 18″ in close second). Following that, I’ll be finishing the project with a Rainier Arms forged upper receiver (without forward assist), Rainier bolt carrier group, and Magpul MOE rifle handguards mounted behind a standard F-Marked front sight tower. For a rear sight, I will likely use the BCM carry handle I already have on hand, but may go with either an LMT sight or Larue A1 style sight in the long run. I plan completing this project before pre-election panic buying gets into full swing, which will make parts dry up pretty quickly. That is, of course, assuming the parts I want are available in my desired timeframe.

 

General

AR-15 Guide for First Time Buyers, Ver 2.0

I decided it was time to revisit one of the most popular posts on this blog: my advice to first time AR-15 buyers.

For a variety of reasons, the AR-15 platform is now the best selling rifle platform in the United States. With that popularity comes competition for your money, and unless you know how this market works, you are very likely to waste money in the process of buying one for yourself. This guide is intended for folks who are relatively new to shooting and are looking through Google, message boards, and other places for help on what to buy. If you have plenty of experience shooting, you will still find this guide useful- but you will be able to skip some of the advice since you probably already have a good grasp of what you are looking for.

DSC_0855

Before getting on with it, I want to explain where I went wrong with my first AR-15 (pictured here). I purchased a stripped lower and immediately started scouring the internet for what I should do with it. Over the course of about 10 months, I purchased each part individually as well as the tools to assemble them. I built a $3,000 carbine that the internet would be proud of. It was a sleek, bad ass looking, SHTF-ready general purpose carbine. It made a fantastic range toy that impressed everyone around me. However, once I actually started using it in local three gun competitions, its shortcomings became immediately apparent to me and I knew it was going to cost me more money to do some things over again. I then built a second carbine taking things back to basics (as I will advocate here). After shooting with that for a bit, I went back to my first AR and rebuilt it using lessons learned from my actual usage.

This brings me to my two fundamental laws of purchasing gear:

  1. Let the mission dictate the configuration
  2. Buy Once, Cry once

Let me explain these.

Let the Mission Dictate the Configuration

As simple as it sounds, this is the most difficult law for people to grasp. The AR-15 is so customizable that most buyers will immediately begin tailoring it to some perceived need even before they fully understand how they are going to use it. It took me years to understand one fundamental truth: a very generic weapon will do reasonably well at just about any task the AR-15 can be used for. The more specialized you make an AR for any particular use, the worse it will perform at others.

The last thirty years have seen an explosion in the possible configurations of an AR. We’veQyFiZ gone from the classic M16A2, to the M16A4, the M4A1 Carbine, the Mk 12 SPR (and it’s shorter cousin, the Recce), the Mk 18 CQBR, and a myriad of others in between. As the internet has filled with pictures of each of these, and the warriors who carry them, there is a certain element of, “I want that!

This sentiment is understandable, these guns all look amazing and they all exist because they have proven useful and reliable. But here is what you have to keep in mind: these configurations all exist to serve as compliments to one another. The M16 series offers the best all-around ballistic performance on an open battlefield, but its extra length will be more difficult when moving in cramped spaces. The Mk 18 and its 10.5″ barrel are great in cramped spaces, but it produces skull-rattling concussion and loses a huge amount of velocity (which limits its effective range). The Recce and SPR fit more into an intermediate category, but their precision optics and stainless barrels make them more useful for precision and less useful for volume of fire (for more information about how barrel length and material affect performance, please read my post on barrels). Everything is a trade off. It’s not a big deal, though, if the taxpayers are buying your weapons for you and you have a squad to outfit with a variety of weapons to compliment each other. It’s a different story if you have to buy them yourself and it may be the only rifle available to you in times of need.

maxresdefaultWhat does this mean to you? As I said before, a generalized weapon (such as the M16 or M4A1) will do reasonably well at any task you throw at them. The specialized weapon configurations really only shine when put in the hands of a skilled and practiced user. Put another way, a NRA high-master shooter will still shoot a chrome-lined M16A2 better than the average joe will shoot a fully customized national match rifle. Special parts and configurations only matter when comparing two skilled users who can take advantage of the capability. If you are a new shooter, you have not gained the skill and experience to even know how you will be employing your weapon, much less take advantage of the nifty gizmos you want to attach to it.

So what do I recommend for a first time buyer? I’ll get to that in a minute.

Buy Once, Cry Once

Don’t be cheap. There is a lot of competition for your discretionary income, and that means there is a lot of marketing dollars spent to sway you to one product over another. One of the worst mistakes you can make is to listen to gun store lore that says Brand X is “just as good as” Brand Y even though it is significantly cheaper. There is no such thing as a free ride. Every reduction in price must be paired with some other reduction in cost to the manufacturer. Typically, these costs will appear in material selection, quality control procedures, manufacturer tolerances, or other areas. If you are interested in the components of a quality AR, please read this post on technical specs.

Like most things, there absolutely is a point of diminishing returns. In the AR world, that point starts at about $1400. In my opinion, the sweet spot is between $900 and that $1400, where you are getting very high quality weapons that you can depend on for protecting your life, your family’s life, and performing in competition. Am I saying that a $500 Model 1 AR is going to fall apart tomorrow? No, not at all. But I am saying that the methods the manufacturer took to get the price point that low could affect the reliability and long term durability of the rifle; and you would have no way of knowing it was a problem until it becomes one (and that usually happens imgresat the absolute worst moment). If you know this weapon is purely a range or hunting toy that you will not bet your life upon, then no problem. If, on the other hand, there is the slightest chance that you might need this weapon to function in a desperate moment- that extra few hundred dollars is cheap insurance.

This doesn’t just apply to rifles, either. I have seen many a shooter buy a cheap red dot sight only to have it break in a couple months. By the time they have bought their third replacement, they have spent as much money on those three optics as they would have spent buying one quality optic up front. If you think a component is worth having, then its worth buying a high quality one at the start. That quality component will last the life the weapon, and probably a couple weapons after it.

Recommendations

Now that I’ve discussed my guiding principles, lets discuss what your first AR should look like. First, you are going to start with a basic configuration that will serve pretty well at just about any task you might have. I suggest only buying a complete rifle, or buying a complete lower and upper separately. At this point, do not attempt to piece together a rifle one part at a time (as I did). You will end up spending more money than you think on tools and shipping. Even then, you don’t have the technical knowledge on properly assembling parts together (especially mounting barrels and checking headspace). Sure, you could take it to a local gunsmith- but unless they truly know what they are doing, you will always wonder if the job was really done right. In that instance, you might be tempted to blame poor performance on the gun rather than yourself. That attitude will only drive you to spend more money on gear rather than ammo and practice. Buying a properly assembled quality rifle up front means any shortcomings are probably yours rather than the weapon’s.

Once you have your new AR, I suggest only spending enough money to get it up to the status of “minimum capable” for whatever it is you want to do. Once there, spend the rest of your money on quality ammunition and some training. Shoot the thing so much that it becomes second nature to you. Compete with it in a variety of styles from CMP/High Power to USPSA. Burn out the barrel. Once you have gone down this route, it will become very obvious where you should spend your money to best suit your needs. By this point, you will have expended enough money in ammunition that the cost of the widget in question will seem….paltry.

All of that said, here is my basic “minimum capable” recommendation for first time buyers. I will discuss variations afterwards.

  • 16″ Lightweight mid-length chrome lined barrel with a fixed front sight base
  • Either plastic handguards (Magpul MOE, Standard Round, BCM) or a quality free floated rail
  • Quality collapsable stock, without being too fancy, containing a H2 carbine buffer and spring (alternatively, I’m a big fan of the VLTOR A5 system)
  • Quality pistol grip of choice
  • Quality (but not fancy) trigger. The fanciest I would suggest at this point would be an ALG ACT or BCM PNT
  • Quality rear sight, with or without adjustment (Magpul MBUS/MBUS Pro, LMT L8A, Daniel Defense A1.5, Larue Lt 103, or even a carry handle from BCM or Colt)
  • If you have the money to buy an optic at this time, then go ahead and grab one that suits your needs- just remember to buy quality (Aimpoint, Trijicon, ELCAN, Zeiss, etc.)
  • Bonus: If you plan on using the weapon for defensive purposes, then you really should mount a white light on it (InForce WML, Elzetta, Surefire, etc.) and learn how to use it properly (i.e., only use in momentary bursts of light)
  • Bonus: You should get a sling.

The rifles below are a selection of various configurations I’ve used that roughly meet the criteria I laid out. The closest two are the one on the top left and bottom right. The top left, with FDE furniture, was my second AR and built with all of the lessons learned from building the first rifle. The second rifle, on the bottom right, was the first iteration of my marksmanship training rifle; it was nearly identical to the FDE rifle except that it had a 20″ barrel and a different stock. That longer rifle is now the one on the top right. The only significant changes are the addition of a free float rail, a muzzle compensator, and a Trijicon TR24. I made these changes only after shooting the rifle for several thousand rounds in a variety of circumstances.

There are many quality manufacturers out there, and I don’t have time to go down the pro/con for each one of them. So, to be blunt, I suggest that your first AR-15 should come from Colt, BCM, Daniel Defense, or Sionics Weapon Systems. These manufacturers all follow a good spec and stick around the same price point. Going much below these manufacturers in price should cause you to ask questions about what was done to reduce costs. Going much above their prices (as with Noveske, KAC, LMT, and others) should make you question if you are paying for a name or features that you are unable to take advantage of. Again, don’t get me wrong, I’m not saying its impossible reduce costs without sacrificing quality (supply chain management is one method of doing so). But I am asking that you don’t play that game with your first rifle since you don’t know a lot about the marketplace.

How did I arrive at this spec?

What separates the first iteration of this guide from the new Version 2.0 is that I have softened my stance a bit on a few things- particularly handguard and stock selection. Let me briefly explain each of theelements, and why I chose them as suggestions for a first timer.

I said a 16″ lightweight chrome lined barrel with a mid-length gas system because I gas-systemsbelieve it will be the most versatile for most people getting started in shooting. Heavy barrels really only shine in applications with high volumes of fire or an increased need for precision over the course of long strings of fire. Neither of those describe the average newbie. I used to suggest a 20″ barrel as well, and it is still a very viable option, but I don’t want to limit folks who might start using the carbine indoors for defending home and hearth.

I still suggest starting with a fixed triangle front sight base as opposed to the new trend of low profile gas blocks and rail-mounted front sights. The traditional triangle post is the sturdiest front sight and gas block you can use. If something has enough force to damage it, then there was probably enough force to destroy the whole rifle along with it. The fixed front sight is useful for point shooting, and works great for times where speed is of the essence. If you decide down the line that you want to mount a longer rail, then you can pay $40 to have it shaved down, or do it yourself, and still have one of the toughest and most rugged gas blocks available.

DSC_0339I still suggest most people should start with plastic handguards, but I’ve come around on the subject. There are many free float handguards on the market that are lighter than even the classic plastic ones. While most newbies will not really be able to take advantage of the accuracy benefit inherent in free floated barrels, it will be there for them in the future once they have practiced enough. The caveat, of course, is that you should do your research and buy quality. I take no sides in the Keymod vs M-LOK debate (though I have been using keymod), both will do the job well enough.

I used to suggest a plain collapsable stock like a Magpul MOE or standard Colt. I’ve backed off of that and will now say to pick a quality stock of your choice. BCM makes a great one, and Magpul makes several options. I suggest collapsable to better suit various shooters’ body mechanics. I’m also a fan of fixed rifle stocks, such as the A1, A2, and Magpul MOE rifle. If your primary usage is outdoors or at the range, a fixed stock has a lot of benefits in durability and smoother functioning (due to the longer action spring). Just remember, if you go the rifle route, you will need a different spring and buffer system than the carbine recommendation I made earlier. It’s up to you to do the homework on weight vs capability and how it affects your weapon. Remember, you should always strive for the lightest component that meets your needs and maintains reliability.

190261When it comes to triggers, I fully understand the temptation to jump for a $200 Geissele or Wilson Combat. I run Geisseles in all of my rifles at this point. However, I will admit that I did that before I could really take advantage of it. I’ve been shooting quite a few rifles with the ACT and PNT triggers, and they are all actually quite nice. They serve as fantastic interim triggers while you decide what route you wish to go in the future: combat two stage, light single stage, or any other variation. Once, and if, you go the route of fancy trigger, you still have a quality backup trigger in the parts bin. If you wish to know more, here is a post all about AR triggers.

When it comes to optics, I used to only suggest red dot sights. However, I realize that RearQuarter1many folks might not have eyes made for irons and red dots anymore. Some folks already know they want to go with magnification. For red dots, stick to the Aimpoint CRO, PRO, or T2 series. The Trijicon MRO has been getting a lot of attention lately as well. For magnified optics, the options are wide and varied. I’m a fan of Trijicon ACOGS and the ELCAN Specter series, but there are many more out there. You’re going to have to do your homework. For a quick overview of the market, here are my thoughts on optic selection.

For bonus items, I mentioned white lights and slings. In my opinion, no defensive rifle should be without a white light. It follows rule #4, knowing your target and what is behind it. Without a light, you might just be shooting at shadowy figures that may or may not be family members. As far as slings go, there are a huge number on the market tailored for various needs. You need to decide if you need one to serve more as a shooting aid, a retention device, or just carrying the rifle in the field. Pick one that suits your desires.

The Final Word

As I stated at the beginning, a generalized carbine will perform well at just about any role that can be expected of an AR-15. The more you start specializing it through fancy barrels, triggers, optics, rails, stocks, and accessories, the worse it will perform at all the other roles you didn’t specialize for. More so, those specialized guns only make a difference in the hands of a skilled user.

Until you have developed the experience and skill, then you really don’t know how you will prefer to use the rifle and what you can do to make it better for you. Until then, it’s all just theory and trying to be cool on the internet. Don’t do what I did.

General

I Have an Itch, and a Vision

For whatever reason, I’ve had an itch lately to build another rifle. The Musket has evolved away from its original purpose as an iron sight training rifle and towards a full fledged fighting rifle. That has also resulted in a commensurate growth in weight. I have an idea for a lightweight iron sighted KISS rifle.

I did a quick mock up on Gunstruction

B+Cfilg06wwtAAAAAElFTkSuQmCC.png

I want to go for a slick sided minimalist rifle as I can get. I have it set up with a lightweight 18″ barrel, fixed stock, basic A1 style sight, and more modern furniture. There is just something very appealing about this configuration to me right now. I went flat top just in case I feel the need to add a red dot in the future.

Hmmmm…..

General

AR-15 Buying Guide: Technical Details

My advice so far has simply been to purchase a basic configuration from quality manufacturers and let them work out the details. However, at some point we all have to start understanding what we are looking at when shopping around. What follows is a breakdown of ads from various AR manufacturers. I will try and explain selling points as best I can, as well as what you should be looking for. In the last five years or so, most manufacturers (even the not-so-great ones) have been shifting their production runs to follow the infamous “chart” of quality AR-15s.

Remember that just because the manufacturer checks off boxes for materials or components, it doesn’t mean that the parts are dimensionally correct. Contracted specification and tolerances still matter. A part can be made from all of the right materials, but if the part has a wide tolerance (meaning it deviates from whatever specification it is supposed to), it can still cause malfunctions.

Ok, let’s start looking at some ads. The first one up is a Bravo Company Manufacturing (BCM) A4 rifle, as sold at G&R Tactical. I started with BCM because I know they are an quality manufacturer who sticks as tightly to accepted specs as possible without blowing your budget.

UPPER RECEIVER:

BCMGUNFIGHTER™ Mod 4 Charging Handle
Receivers Machined from Aluminum Forgings 7075-T6
Receivers Hardcoat Anodize per MIL-A-8625F, Type III, Class 2
M4 Feed Ramp Flat Top Receiver
Detachable 600M Carry Handle Rear Sight
T-Marked Upper Receiver

BARREL:
Independently Certified Mil-Spec 11595E Barrel Steel 20″ USGI M16A4 Government Profile Barrel
1/7 Twist Rate
HPT (High Pressure Test, per Milspec) Barrel
MPI (Magnetic Particle Inspected, per Milspec) Barrel
M4 Feed Ramp Barrel Extension
USGI 5.56mm NATO Chambers
Chrome Lined Bore and Chamber
Mil-Spec F-Marked Forged Front Sight
Taper Pinned Front Sight Base
Manganese Phosphate Barrel Finish on Entire Barrel

GAS SYSTEM:
Rifle Length Gas System

BOLT:
Bolt Machined from Mil-Spec Carpenter No. 158® Steel HPT Bolt (High Pressure Tested/ Proof)
MPI Bolt (Magnetic Particle Inspected)
Shot Peened Bolt
Tool Steel Extractor

CARRIER
Chrome Lined Carrier (AUTO)
Chrome Lined Gas Key
Gas Key Hardened to USGI Specifications
Grade 8 Hardened Fasteners Key
Staked Per Mil-Spec
Tool Steel Extractor
BCM® Extractor Spring
Black Extractor Insert

LOWER RECEIVER:
Receivers Machined from Aluminum Forgings 7075-T6
Receivers Hardcoat Anodize per MIL-A-8625F, Type III, Class 2
Low Shelf for RDIAS Installation – Installation of a registered drop-in auto sear allows weapon to fire on full automatic
Low Shelf for Accuwedge Use – Accuwedge Stabilizes fit between upper/lower receiver
Un-notched Hammer Compatible with 9mm Use
Fire Controls Marked SAFE and SEMI
Magpul MOE Enhanced Trigger Guard
BCM® Milspec 7075-T6 Receiver Extension
A2 Fixed Stock

WEIGHT:
7 lbs 12 oz

That is a pretty thorough list, which is why I started with it.

Starting with the receivers, note that they are both machined from forgings of 7075 aluminum. This process means that the aluminum was hammered into shape by a large forging press, and then all of the cavities and holes were machined out. The alternative to forging is billet, where a block of aluminum is placed into a CNC machine and “sculpted” into a final design. Forging may produce a slightly stronger receiver due to the compression of metal grain (similar to the slightly increased strength of hammer forged barrels). Billet receivers may have tighter tolerances, leading to better fit of components and better accuracy. Billet can also be carved into more fancy designs.

7075 should be your go-to for AR15 receivers. The other common alternative, 6061 aluminum, was the original specification in the early 1960’s due to easier machining (7075 is more than 50% stronger). Experience in Vietnam showed that forgings of 6061 were extremely prone to corrosion in humid environments. Daniel Watters’s excellent history of the 5.56 cartridge mentions examples of takedown pivot holes completely rusting through in as little as three months.

The T6 refers to the type of heat treatment used on the aluminum.

The BCM receiver extension, also known as the buffer tube, is also made from 7075-T6 aluminum. Not a lot of manufacturers will specify what their buffer tubes are made from. In many cases, less expensive rifles may say the receivers are 7075, but the buffer tube may be 6061 in order save some money.

The specs reference M4 feed ramps on both the upper receiver and the barrel. M4 feed ramps are a more recent development that came about in the 90s. They came about in order to increase the feeding reliability of the M4 carbine when fired fully automatic. The original AR-15 system, and its rifle feed ramps (which exist only on the barrel extension), was not designed to operate at the higher pressures and cyclic rates of the short carbine system. The bolt carrier did not always get a firm hold of the next cartridge for feeding, which resulted in malfunctions. To compensate, the feed ramps were extended to run from the barrel extension onto the upper receiver. Note that this development really does not affect civilian shooters with semi-automatic only weapons, but the perceived increase in reliability meant that the M4 feed ramp pattern became ubiquitous. The full size M16A2 and A4 still use the old rifle ramps, but most civilian ARs come with M4 ramps. What you need to keep in mind is that the ramps on the barrel and receiver should be matched. It is OK to use an M4-ramped barrel extension on a rifle-ramped receiver; but using a rifle-ramped barrel extension on an M4-ramped receiver will cause malfunctions. This latter combination results in a distinct “lip” that overhangs the receiver’s feed ramp, and the nose of bullets will get caught in it.

Comparison of various AR feed ramp configurations

‘T-Marked’ simply means that there are markings to let you know what part of the rail you are using. The intent is help keep you be consistent when you attach and detach various accessories.

The barrel has these specs:

Independently Certified Mil-Spec 11595E Barrel Steel 20″ USGI M16A4 Government Profile Barrel
1/7 Twist Rate
HPT (High Pressure Test, per Milspec) Barrel
MPI (Magnetic Particle Inspected, per Milspec) Barrel
M4 Feed Ramp Barrel Extension
USGI 5.56mm NATO Chambers
Chrome Lined Bore and Chamber
Mil-Spec F-Marked Forged Front Sight
Taper Pinned Front Sight Base
Manganese Phosphate Barrel Finish on Entire Barrel

The military spec for the barrel steel is a 4150 Chrome Moly Vanadium (CMV) alloy, specifically known as Mil-B-11595E. This blend is well understood, having been originally spec’d in 1966. 4150 reflects better hardness and heat characteristics over the slightly cheaper 4140 blend, but the average shooter is not likely to push a barrel to the types of temperatures that would seriously cause problems. If you want to deviate from a standard mil spec barrel, check out my post concerning AR-15 barrels. Barrels are an instance of the ‘spec’ being just a commonly accepted standard, you can buy great barrels for less money that follow a different spec sheet.

High pressure testing and magnetic particle inspection mean that the manufacturer fired a high pressure “proof load” through the barrel, then used a process to look for imperfections and weaknesses that may lead to later failure. As you will see later, this is also done on the bolt for the same reason. The intent is to make sure that the part will not fail you prematurely. Some manufacturers, like BCM, will do this on every bolt and barrel they sell- which raises costs. Others will do it on a few barrels from each batch. Others might not do it at all. I have seen one manufacturer state that doing the value of MPI is greatly diminished without doing the HPT first, so keep that in mind when you see only one or the other. I have also seen another manufacturer of very high quality rifles state that they no longer do these tests out of concerns that the test actually shortens the life of the component.

This rifle has a 5.56 NATO chamber. What you need to know is that a 5.56 rifle can fire 5.56 or .223, but the same is not true in reverse. 5.56 NATO is a higher pressure round than .223. A .223 chamber may not have enough space for the extra gas of 5.56, and could result in a catastrophic failure. For that reason, most people look for a 5.56 NATO chamber in their AR-15, since it allows the use of cheap surplus ammunition. However, .223 chambers are slightly more accurate- so keep that in mind. There are various hybrid chambers out there, like .223 Wylde, that can comfortably shoot both.

The barrel bore and chamber are chrome lined. Again, this is the military standard, but you don’t need to follow it if you go for a different barrel material or lining type. Melonite (also called salt bath nitride, QPQ, and other names) is a surface conversion/hardening process that provides good corrosion resistance without the loss in accuracy of chrome. However, be advised that it is a fairly new process, and the temperatures that the barrel must be heated to are pretty high- the long term effects of heating the barrel in such a manner are not well understood. Buy quality and let the manufacturer worry about how it gets made.

url.jpgThe F-Marked and taper pinned front sight base is another indicator. An F-Marked base means that the shelf of the front sight is the correct height for detachable carry handles. Keep in mind that nearly all rear sights made today are intended to work with f-marked front sight bases. If you don’t have one, then you will have to adjust the front sight pin high enough that the base of the pin may become exposed. 

Taper pinning means that the barrel has two grooves drilled on the bottom, and the front sight is secured by wedging steel pins through the sight and grooves. This is the most secure way to attach a front sight or gas block. There are two downsides to taper pinning, though. First, any removal of material from the barrel in such a non-uniform way could result in changing the harmonic vibration of the barrel during firing, which means decreased accuracy. That is why a lot of match rifles will have clamp-on gas blocks. Secondly, taper pinning is unique to the front sight or gas block you are using. You cannot simply remove the base and put another one in its place. Quality manufacturers not only pin the FSB in place, but they also make sure that it is straight. Some budget brand ARs will have the FSB pinned, but it will be crooked- and there is no fixing it once the pin holes are drilled.

If you want to switch to a different style of gas block or front sight, you will have to deal with the grooves from drilling the old one. This is why people with fixed front sight bases, as I advocate for new buyers, will turn to shaving down the front sight instead of replacing it with another gas block entirely.

Manganese phosphate is simply an outer coating to give the barrel its unique black look and offer some environmental resistance. There are lot of coatings out there, so don’t get hung up on any particular one. Something to look for, though, is that the manufacturer actually put the coating on the barrel before they pinned the FSB in place. Inexpensive barrels may be bare steel under the FSB, and you would never see it.

The bolt carrier group has these specs:

BOLT:
Bolt Machined from Mil-Spec Carpenter No. 158® Steel HPT Bolt (High Pressure Tested/ Proof)
MPI Bolt (Magnetic Particle Inspected)
Shot Peened Bolt
Tool Steel Extractor
BCM® Extractor Spring
Black Extractor Insert

CARRIER
Chrome Lined Carrier (AUTO)
Chrome Lined Gas Key
Gas Key Hardened to USGI Specifications
Grade 8 Hardened Fasteners Key
Staked Per Mil-Spec

The bolt is made from Carpenter-158 tool steel. Again, this is the contracted military specification, but that doesn’t mean it’s necessarily the “best” option. Always remember that government contracts will typically go the cheapest path that meets their reliability needs. Lewis Machine and Tool (LMT) has written that Aermet is a better steel for bolts, as it is 2.5 times stronger- but it’s also quite a bit more expensive (and wasn’t available when the original spec was written). The bolt carrier is typically 8620 steel (this isn’t listed).

The bolt should be shot peened, which increases the resistance of the bolt to fatigue. Many people suggest only buying bolts that have been individually high pressure and magnetic particle inspected, as with barrels. The same thing I said about barrels applies here.

Tool steel extractor simply means that the extractor is better than soft pot metal. The more important part here is the better springs and inserts, which provide a stronger “grab” on the base of the brass for positive ejection. 

When it comes to bolt carriers, there are very few reasons you should not be running an M16 AUTO carrier. That means that the carrier is the same dimensions and weight as the original select fire design. This does NOT mean that your rifle will fire fully automatic. The AUTO refers more to the weight and dimensions. You can see the difference below. The lighter commercial AR-15/semi auto carriers can negatively affect reliability and are really only used today for lightweight operation in competition rifles- and even those styles (like the JP LMOS) are much better designed.

boltCarrier.gif

You will also notice that the BCM advertises staked gas carrier keys. Staking is important! Staking is the process of indenting fastening screws in certain key areas to prevent the fastener from backing out. You should not see anyone using Locktite or other thread lockers on these areas- they should be staked into place. This includes the bolt carrier gas key (two screws, staked twice each), and the castle nut of a carbine buffer tube (not required on a rifle buffer tube, but you will see that the BCM carbine advertises staking on the castle nut as well).

 

Because I used an A4 rifle in this example, something that is not listed in these specs is the mil-spec receiver extension used on carbines (the carbine link I posted has it, though). Receiver extensions should be 1.14″ in diameter, also known as “mil spec” (as opposed to “commercial”). I don’t see commercial extensions very often anymore, and I think the industry has more or less settled on the “mil spec” tube. If going the rifle buffer route, then disregard these dimensions and simply worry about the material.

buffertubescivmil.jpg

The rest of the listed specs on this rifle are pretty self-explanatory, so I won’t go into them. What I’ve presented here is pretty much what you should be looking for as a base standard. What I want to do now is post some spec lists from other manufacturers so you can sort through them.

First up is a fairly new company on the market making a name for themselves, Sionics Weapon systems. This is their Patrol Rifle Zero, which fits in the same category of basic carbines that I advocate for first time buyers.

Here are the specs

Configuration: M4 Style Carbine
Upper Receiver: 7075 T6 with M4 Feed Cuts and T-Markings
Barrel: 16” Medium Weight Contour, CMV 4150, 5.56 NATO Chamber, 1:8, Chrome Lined Barrel and Chamber, Air-Gauged, Radiograph and MP Inspected
Gas System: Mid-Length, Direct-Impingement
Front Sight: F-Marked Front Sight Base
Rear Sight: A2 Aluminium – Manual Folding
Muzzle Device: A2 Flash Suppressor
Bolt Carrier: 8620 M16 Profile Carrier. NP3 Coated
Bolt: Carpenter No.158, HP/MPI Tested, Black Insert and Sprinco 5-Coil Extra Power Extractor Spring. NP3 Coated
Charging Handle: USGI
Lower Receiver: Forged 7075-T6 Aluminum
Trigger: SIONICS Enhanced Mil-Spec
Lower Receiver Parts: All standard Mil-Spec parts
Receiver Extension: 6 Posistion Mil-Spec (Dry Film Lubricated)
Buffer: Carbine “H” Buffer
Stock: B5 Systems SOPMOD Bravo
Grip: ERGO*
Hand Guard: Magpul MOE
End Plate: IWC QD
Extras: Magpul 30 Round Magazine
Rifle Weight – 6 lb. 13 oz.

How many items hit the specs? It looks to me that the important ones are covered, with some other flashy things thrown in (NP3 coating, for instance). Some things are not mentioned, however- such as the receiver extension material or staking. For these items, you have to rely on reputation of the company, emails with specific questions, or looking at photos of their products.

Let’s look at a ‘budget’ AR that someone at the local gun shop might be interested in if they didn’t know any better. This is a DPMS Panther Arms sold at Cabela’s for $599.

7075-T6 upper and lower receiver
16″ 4140 Chrome lined barrel with 1/9 twist
Commercial buffer tube

Not a lot of information there, honestly. But you can see that they use a cheaper grade of barrel steel with a 1/9 twist. The commercial buffer tube is unfortunate, since it will not be compatible with most of the stocks on the market. No information is given about the internals, what they are made from, and how they are assembled.

Here is another common one, Smith & Wesson M&P 15 Sport II ($650)

The Smith & Wesson Model M&P15 Sport™ 5.56mm NATO Semiautomatic Rifle features an adjustable A2 Post front sight and an adjustable Dual Aperture rear sight. The rifle is designed with a 6-position telescopic stock and a 4140 steel barrel with a Melonite® finish, as well as an aluminum receiver with a hard-coat black anodized finish. 30-round detachable PMAG® magazine.

Features and Benefits
Semiautomatic firing
6-position telescopic stock
Adjustable A2 Post front sight and adjustable Dual Aperture rear sight
Chrome-lined gas key and bolt carrier
Made in USA
4140 steel barrel with a Melonite® finish and a 7075 T6 aluminum receiver with a hard-coat black anodized finish

Again, a cheaper 4140 barrel. The barrel is 1/8 twist and Melonite, which are both fine. Also, no mention of internals, materials, and manufacturing methods. Now, my own research shows that S&W does do a lot of the right “stuff” with their rifles, they just don’t advertise it like the enthusiast/professional grade companies do.

One more. This is a Del-Ton Inc (DTI) carbine. It retails on their web site for $753.

Barrel:
  • Chrome Moly Vanadium
  • M4 Feed Ramps
  • 16″ Length
  • 1×9 Twist
  • A2 Flash Hider
  • Manganese Phosphated
  • Phosphated under Front Sight Base
  • Taper Pins on F-Marked Front Sight Base
  • Threaded Muzzle
  • M4 Profile

Chamber:

  • 5.56 X 45 mm
Bolt And Carrier:
  • Phosphated 8620 Steel Carrier Assembly
  • Carpenter 158 Bolt HPT/MPI Tested
  • Heat Treated and Plated
  • Mil-Spec
  • Chrome Lined Carrier Interior
  • Carrier Key – chrome lined, attached with Grade 8 Screws
  • Properly Staked & Sealed Gas Key
Handguards:
  • Carbine Length
  • Aluminum Delta Ring
  • Single Heat Shield
Upper Receiver:
  • Forged 7075 T6 Aluminum
  • Flat Top With M4 Feed Ramps
  • Hard Coat Anodized
  • Mil-Spec
  • Ejection Port Cover and Round Forward Assist
  • Right Hand Ejection
  • Bore’s surface is coated with dry film lube, over the anodized surface
Lower Receiver:
  • Forged 7075 T6 Aluminum
  • Hard Coat Anodized
  • Mil-Spec
  • Aluminum Triggerguard
  • Semi-Auto
  • Aluminum Mag Catch Button
Buttstock:
  • M4 5 Position
  • Reinforced Fiber
  • Mil-Spec Buffer Tube
Weight:
  • 6.4 lbs Empty

From the spec list, this actually looks like it hits all the important points (except for 1/9 twist and an unknown blend of CMV on the barrel steel). However, my question then becomes: how are they selling them cheaper? This is where you have to make that judgement call. They may check all the right boxes, but what about the contracted specs of those parts, the assembly process, and the quality control methods?

I want to note that I’m not saying these brands are bad. I’m just pointing out that they either don’t follow the accepted standard or at least don’t advertise that they do. All of the companies I’ve found that do stick to the standards, or exceed them, charge about the same price for their weapons (Colt, BCM, Sionics, Daniel Defense, etc.). Companies that charge significantly less tend to change what goes into their weapons. How you decide from there is up to you.

Thanks for reading!

General

Point Blank Zero

I previously wrote about the relationship between a bullet’s ballistic coefficient, velocity (and therefore barrel length), and choice of zeroing distance  along with associated effects on shot patterns at various ranges. The Swiss took advantage of this relationship with their S4G system (Sniping- 4th Generation).

As Colorado Pete pointed out in the comments last year, this concept has existed for a while as something called the point blank zero (PBZ). In short, this is the zero distance for a given rifle and load combination that keeps your shots within a desired radius while using the same point of aim. For example, consider a vital zone size of eight inches in some large game animal. The PBZ would be the zero in which the bullet would impact no more than four inches above or below point of aim, which is the center of the vital zone. A larger vital zone means a more generous point blank zero; a smaller vital zone means a restricted one.

How does this concept work?

Recall that a bullet does not fly in a straight line. Rather, it flies in an arc. The characteristics of this arc are the result of the aerodynamic shape of the projectile (the ballistic coefficient, or BC) and the velocity it is traveling. The BC and velocity are consistent from shot to shot. The only thing affecting the shape of the arc is the angle at which the projectile is launched- which you control by adjusting the elevation turret. In a practical sense, this alters where the bullet initially crosses your line of sight, how high it will reach (also known as the maximum ordinate), and where it intersects your line of sight again as it falls.

15n9742.jpg

The end goal of a PBZ is to choose a maximum ordinate and a point below the line of sight that encompasses the acceptable target area. If your shot falls anywhere within this imaginary circle, then it is considered a good hit.

JBM Ballistics has a fantastic calculator that takes a lot of the guess work out of this for you. All you need to do is feed it your ballistic data and the desired “vital zone” radius. For this chart, I am using Sierra 69gr SMK fired at 2750 fps (as I recently measured on the musket). My desired vital zone radius is six inches (meaning a 12 inch total vital zone). Notice that the chart tells me exactly what the calculated PBZ should be for my desired 12″ zone, and what distance that point blank range (PBR) is good for. It also tells me the range of maximum ordinate (161 yards, about 6″ above line of sight).

JBM Tbl 3.png

According to the calculator, the best point blank zero to maintain a 12” target is 291 yards. The calculator predicts that the maximum range I can use this zero is about 341 yards.  If I go back into the calculator again using the same ballistic data, and make my zero 291 yards, then you can see how the data shakes out.

JBM Tbl 2.png

Of course, zeroing at exactly 291 yards it not terribly practical, but you can use it as a guideline. Increasing my zero to 300 yards gives me effectively the same result, with a drop of 6.2 inches at 350 yards. Using this data, it’s easy to see why the Army and Marines were drawn to the 300 meter zero (I know, meters are not the same as yards, but the data works out pretty close). 

A challenging aspect of this type of zero is remembering to account for the maximum ordinate. With this zero, the bullet will be about 6 inches above the line of sight at 161 yards. If you are aiming for a small target (such as a small gong, or a headshot), then you are liable to miss high if you simply aim for the middle of the target. PBZ works best for center-mass aiming. If your target is smaller, then you need to adjust your radius and zero to compensate. This is the reason for the ubiquitous 50/200 zero, since it supposedly keeps the bullet +/- 2 inches over line of sight until about 250 yards. Note that the 50/200 is notional and based on military load data and velocities, your actual zero may vary (mine is closer to a 30/200).

Alternatively, the A-zone of an IPSC target is eight inches tall. JBM tells me that a 250 yard PBZ works best for that size, keeping me +/- 4 inches out to about 300 yards.

Applying PBZ to Different Reticle Designs

The above concept works well for your average duplex reticle found on millions of hunting rifles. But what about other reticle designs? You can combine PBZ with various reticle shapes to determine more aiming points.

For instance, my Trijicon TR24G has a nice glowing triangle sitting atop a post. However, the heavy post prevents me from having usable holdover positions beyond the bottom edge of the triangle. According to Trijicon, this triangle, at 4x magnification, is 4.2 MOA tall. Since it is second focal plane, it is 12.8 MOA at 1x, and 8.4 MOA at 2x magnification.

IMG_0350

JBM does not produce a nice easy PBZ based on minutes of angle, but it does still produce MOA drop values. You will have to input various zero distances until you arrive at an acceptable solution. If I wanted to keep my impacts to about 4.2 MOA above or below the point of the triangle, then it turns out about a 275 yard zero works best. Again, rounding up 300 yard zero with the tip of the triangle means that the bottom of the triangle is at about 410 yards, and that is probably an easier zero to choose, since it keeps consistency with the previous PBZ.

The different MOA subtensions of the reticle at lower magnifications can also be put to use. If I zoom down to 2x, the bottom of the triangle is now 8.4 MOA from the tip, which correlates to a 500 yard aim point. At 1x, that same point now gives about a 600 yard aim point. That is, of course, assuming you can even see the target.

This method works reasonably well for any optic that does not have some form of range markings (either as a BDC as in an ACOG or my ELCAN, or as hash marks in an MRAD reticle).

A 25 yard zero actually works out very well for this combination of rifle, load, rifle, and optic. A 25 yard zero keeps me +/- 3 inches out to 250 yards. The bottom of the triangle correlates to about a 350 yard aiming point. At 2x, the bottom of the triangle is about 450 yards, and 550 yards at 1x. Not bad for such a simple triangle.

In the end, you have to imagine two opposing ends of a line. On one end is speed, and on the other is precision. Which is more important to you for the most likely shot you are going to take? For hunting or self-defense at reasonably close distances (inside 200 yards) on fairly large target zones, a PBZ method is very effective. For fast-paced timed competition, the PBZ is workable with a well-chosen zero. If you need to hit small targets at longer ranges, then you might need to shift more towards precision-oriented zeroing methods and optics.