My post concerning the first impression of the AFAB got me thinking about this subject. Most people use the terms interchangeably, but they’re really not. In fact, companies even mix up the phrases. For instance, Precision Armament’s AFAB (which stands for Advanced Flash Arresting Brake) is actually designed to be a compensator, and their very well performing M4-72 Severe Duty Compensator is actually a brake (unless you add in the word recoil, making it a Recoil Compensator, as found on tanks, cannons, and other large weapons).
So what’s the deal?
Strictly speaking, muzzle brakes (and recoil compensators) are designed to vent expanding gasses in a way that reduces the recoil forces felt by the shooter. More specifically, they reduce the rearward recoil momentum so that the gun feels “softer.” This has the advantage of reducing shooter fatigue, especially with larger calibers.
Muzzle brakes are characterized by large gas venting ports, often pointing rearward. This pattern directs expanding gasses back towards the shooter and “pushes” the rifle forward to counter the momentum from a projectile exiting the barrel. This often comes at the price of monstrous muzzle blast and concussion, usually far louder than a rifle with no muzzle device at all.
Muzzle compensators, on the other hand, do not necessarily reduce that rearward motion, but attempt to vent gasses in a pattern that keeps the muzzle stable- reducing “muzzle jump.”This helps the shooter have faster follow up shots, or have a better chance of watching the effect on target. These are also associated with increased noise and concussion, but usually less than dedicated brakes.
There are a myriad of reviews out there comparing muzzle devices from several companies. One of the failings in these articles, in my view, is that they usually only measure one aspect, such as rearward recoil force. In these tests, the pure muzzle brakes (like the M4-72) perform the best, and the compensators will perform somewhere in the middle of the pack. A proper comparison would look at both the rearward recoil forces as well as muzzle deflection.
Vuurwapenblog did a pretty good job in this regard, though his selection was rather limited compared to something like the TTAG’s brake shootout (which only looked at rearward recoil). That’s no fault of his own, these kinds of projects take time and funding beyond what us normal people normally have.
Thus far I have not mentioned flash hiders. I believe most people are familiar enough with them already. They are designed to vent gas in a manner that reduces pressure (and temperature) to reduce the flash signature of unburned powder. They are not really designed to do anything about recoil.
The AR-15, and the .225/5.56 cartridge in particular, is not known for heavy recoil. Because of that, there is a lot of effort put into hybrid devices that try to do a little of everything. They may have several vents and port sizes designed to spread gasses in different directions and patterns to both reduce recoil, hold the muzzle stable, and reduce flash. In general, as is usually the case, they will be outperformed by devices designed to do only one of those things well. That’s not to say hybrid devices don’t work; they will do their tasks well enough.
There you have it! Muzzle brakes mean less felt recoil at the expense of much more noise and blast. Muzzle compensators mean a more stable point of aim during recoil, at the expense of slightly more noise. Flash hiders mean less flash in the dark with little to no increase in noise and little help with recoil.