I posted my initial impression of the AFAB last month. The machining of the device is top notch, and I’m not entirely sure how they are charging as little for the device as they are. Since that post, I went ahead and purchased some armorers tools (Magpul armorer’s wrench and a Geissele reaction rod) so that I could do the job myself.
I received the AFAB, which stands for Advanced Flash Arresting Brake, as a Christmas gift from my lovely wife. The device is a hybrid of muzzle compensator and flash hider. Precision Armament has gone through a few revisions of the design: AFAB, AFAB Mini, and then this newest AFAB 556 that replaced both of the previous generations. The company settled on this final design using some lessons learned while designing a sister device, the EFAB (Enhanced Flash Arresting Brake, pictured to the right).
The AFAB is 2.225″ long and .865″ wide and weighs 3 ounces. It is made from 416 steel bar and finished with black matte ionbond. It retails for about $110, which is slightly more than other devices in its class but less than the very popular Battlecomp (and way less than anything with KAC on the side of it). In comparison, a standard A2 flash hider is 1.75″ long and .875″ wide. It is made from 4140 CMV steel, weighs about 2 ounces, and retails for about $9.
The machining on the AFAB is top notch. It is very clean, with no sharp edges or burs to be seen. There is a pin hole pre-drilled on the 6 o’clock side for pinning/welding the device on a 14.5″ barrel. At the corner of each exterior square is a small vent hole drilled into the internal cavity. There are no vent holes along the top or bottom. On the inside, there are a series of concentric chambers that help capture expanding gasses and redirect them through the vent holes. The squares on the outside appear to assist with the flash arresting nature of the compensator. At the front end of the device is a fairly typical three prong configuration found on many other flash hider designs.
Installation is straight forward. Precision Armament explicitly says that the AFAB should not be mounted using a crush wafer. As with suppressors, the tolerances on the inside of the AFAB are pretty tight, and any misalignment could result in the bullet striking the internals of the device rather than cleanly exiting through the front. They recommend a shim kit, of which there are several on the market. Note that if your muzzle threats are poorly cut and not concentric with the bore, then even a shim kit may not stop the bullet form impacting the internals (which again, is why I keep repeating how important it is to buy from quality manufacturers). I picked up Precision Armament’s own Accuwasher kit for $25. This kit comes with 18 different washers of varying thicknesses. They are marked with a series of thin and fat hash marks to signify where they fall in the sequence of 1-18. Each increment equates to about 20 degrees of rotation. The kit also comes with easy to use instructions, and should be good for installing an average of nine devices. Once I had everything I needed, I set off to installing it on the 20″ musket.
To mount, you place the thickest washer on the shoulder of the muzzle and then hand tighten the device. You then eyeball about how much more rotation you would need and choose the corresponding washer (the instructions also have a handy chart correlating the amount of rotation needed with the correct shim). In my case, I needed about 270-280 degrees of rotation.
Once the shim is in place, simply tighten and torque the device into place with 20-30 ft lbs. I did this once, backed it off, applied some Rocksett, and torqued it into place again. Easy. So easy, in fact, that I may go back and reinstall all of my other muzzle devices using these shims. As a tip, you should try to use the minimum amount of torque necessary to index/time the device. Using excessive force can cause problems with crown deformation as the muzzle heats during repeated firing. I recall reading that the Army Marksmanship Unit runs devices just past hand tight on their rifles for this reason.
Once I got to the range, I immediately putting the AFAB through its paces. In short, this is a fantastic little compensator. The musket is now one of the smoothest and most stable rifles I have ever had the pleasure of shooting. Keep in mind, though, that the musket was already a very smooth shooting rifle. The addition of the AFAB simply made the muzle extremely stable, almost like shooting a laser. From nearly any position I tried, I found that the sights stay on target very well. My primary use is slow fire, but I found rapid fire to be very easy to keep the rifle still and keep the sights aligned.
I cannot say that the AFAB is much louder or quieter than the A2 I was running before, but I did note that the report has a sharper pitch to it. The BCM Gunfighter comp on my 16″ AR, which I also brought along, sounded much louder and had much more concussion with each shot. I’m sure the muzzle report of the AFAB would be louder if I put it on the 16″ barrel instead of 20″ due to the increased pressures, but I simply don’t have the time or equipment to do such a thorough comparison.
A 20″ barrel is not really a fair test of a muzzle brake/comp, though. The reduced muzzle pressure and complete burn of powder charge means that just about any device will perform well. The real test is on shorter guns with higher pressures. From my reading of others who use the AFAB, it performs equally as well for them as it does for me.
Something else to keep in mind with the AFAB, which is true of all closed chamber muzzle brakes like the Battlecomp, Spikes Dynacomp, Griffin Flashcomp, and others is that there will be a slight increase in bolt carrier velocity as it cycles. This is due to a little bit more resistance around the muzzle, causing just a bit more back pressure (though nowhere near as much as a full suppressor would). With my 20″ rifle gassed system operating on a full weight BCG and Sprinco Green spring, the effect is negligible. If you are running a shorter system, then be aware that a closed chamber compensator like this may actually increase your felt recoil at the shoulder (as minimal as it is on a 5.56 cartridge). I would argue, however, that this effect is mitigated by the extremely stable muzzle. Remember, compensators serve a different purpose than muzzle brakes.
I did not test low light conditions, but the word is that the AFAB performs admirably. This is a photo I found showing the previous generation AFAB-mini next to an A2 flash hider and a “Leading Multi-Purpose Flash Hider/Compensator” (my guess is a Battlecomp). I would note that the AFAB 556 that I installed has supposedly further improved on the AFAB-Mini’s flash suppression.
From the looks of it, the AFAB has more than adequate flash mitigation for a hybrid device. It won’t perform as well as a dedicated advanced flash hider such as the AAC Blackout, Smith Enterprises Vortex, or a BE Meyers 249f, but it still does a decent job. In fact, TTAG did a more scientific comparison of several flash hiders and hybrid designs, and the AFAB performed quite well, especially for a hybrid design.
Should you buy this comp? I’ll put this in the category of, “Why not?”
The AR-15 is already a soft recoiling weapon. Muzzle stability can be achieved with proper training and without the addition of muzzle devices. With a full size AR in the 20″ class, this devices makes an absolute pussycat of a rifle, and would be very comfortable for new shooters. It also makes it quite stable for less-aggressive positional shooting where your body mechanics don’t allow for vigorous muzzle control.
On a shorter weapon, I can see the benefit of a device like this for those who want to go fast and shoot fast. It does help greatly with muzzle stability, and does not present the usual problems with muzzle flash that comps and brakes are known for.
If you already have a flash hider, comp, or brake that you enjoy shooting, then I don’t think you would see any great benefit of switching to the AFAB.
The Final Tally
- Very nice machining
- Looks very cool
- Great compensator performance
- Low muzzle flash for a compensator device
- Little increase concussion/noise over A2
- Relatively high cost
- Requires purchase of additional shim kit (so don’t forget to factor it into the price)
- Adds almost half an inch to the length of the weapon over the A2
Rating: Buy it if you want to, as it does great work at the things it is supposed to do. But don’t use it as a substitute for proper shooting form.