Choosing between a flash hider and a muzzle brake for your quick-detach muffler mount depends on many factors.
Some of the most interesting topics I wrestle with come to me in the form of excellent questions from fellow riflemen and women. When one of these questions comes up repeatedly, I know it’s time to give it more than passing attention. So it is with a new twist on the muzzle brake versus flash hider debate. Specifically, which is better to use on a rifle that will be suppressed most of the time or all of the time? The “best” part of this question can be broken down further into which device is more durable and which offers better sound and flash performance in conjunction with a sound suppressor.
Whenever this question has been asked, I have done my best to base the answers on my own experience as a shooter and weapons developer/tester in the military. My quick answer is that a muzzle brake will generally be stronger, based purely on the theory that more metal is better. Performance wise, I never noticed any flash differences between the two types of muzzle devices when a suppressor was fitted. Since much of my hearing was taken over by a series of rapid explosions 20 years ago, I can’t answer the sound suppression part of the question. Because my explanations were limited to the non-technical realm of “Grunt-speak”, I contacted SureFire’s Suppressor Division for any clarifications and course corrections they might apply to my boilerplate answers.
According to SureFire, when a suppressor is fitted most or all the time, muzzle brakes tend to be more durable than flash hiders due to their thicker structures. The company explained that baffled muzzle brake designs, such as its own SOCOM series brakes, also provide a sacrificial deflector that gases, heat and particles hit before entering the muzzle suppressor and encountering the blast deflector. However, SureFire points out that the blast baffles on its suppressors are very thick and made of Inconel, while the muzzle brakes are usually stainless steel. Therefore, the blast deflector should be much stronger than the brake (or flash hider) and almost impossible to wear out during normal use.
When it comes to flash suppressors, SureFire’s Suppressor division points out that the thickness of its open-tooth flash suppressors makes them very durable when subjected to the heat, pressure and erosion that comes with firing with a mounted suppressor. While brakes tend to be stronger than flash hiders, SureFire points out that the heavy use required to cause the flash hider to fail will also wear down the barrel and other critical components in the process. Closed-tooth flash hiders are less durable than open-tooth models because the front part (connecting the streamers) is quite thin compared to the thicker teeth of an open-tooth flash hider. The closed end catches more blast erosion, while an open-tooth design allows blast and erosion to pass through and into the sound suppressor. SureFire adds that some military customers use extremely durable QD muzzle devices made of Inconel, but since they cost four to five times more than stainless steel, these brakes and flash hiders are impractical for the commercial market.
Does a muzzle brake or flash hider work as a suppressor mount?
When considering how muzzle brakes compare to flash hiders in terms of suppressed performance, the script backfires slightly. SureFire reps tell me that muzzle brakes tend to direct more blast to the rear of the suppressor causing carbon to build up on the mounting surface of the device faster than when a flash hider is used. I can certainly attest that this additional buildup is noticeable and requires more frequent cleaning of the brake mounting surfaces to ensure proper suppressor attachment. Sonically, SureFire states that it is essentially a mix between the two muzzle devices when a suppressor is fitted. Likewise, the flash visible outside the suppressor is not significantly different from device to device.
Anyone who has tried both an oversized suppressor and a bore-specific design on the same gun, such as the .22 and .30 caliber centerfire suppressors on a 5.56mm rifle, has probably noticed that the smaller suppressor bore provides better sound and flash. reduction. SureFire verifies that this observation is not imaginary. However, the company adds that a larger suppressor bore size outperforms a tighter size in the accuracy department, especially on large caliber rifles. Another helpful nugget passed down from SureFire is that overbored suppressors stay cooler, which reduces wear, compared to tighter bore sizes. This can be useful when planning shorter barrels or high volume shots.
Eighteen years ago, as I transitioned from someone who used sniper and close quarters rifles to a tester and developer of new weapon systems, QD muzzle suppression device failures were something with which we lived. Under heavy use, the fine teeth of these earlier flash hiders could melt and/or weld inside their suppressors in one heavy shooting session. Both items would be ruined in the process. Long before such damage occurs, a failing suppressor mount will pull a suppressor out of proper bore alignment, risking knocking baffles and end caps along with other nasty results. Today’s QD muzzle devices, internal suppressor designs and materials are far superior to what was considered standard fare just a few years ago, making mounting surface failures much less common.
Since I rely primarily on input from SureFire’s Suppressor division, the caveat “actual results may vary” applies here. Although some manufacturers’ internal test results may differ from SureFire’s, I feel comfortable applying the basic principles of flash hider and muzzle brake performance suppression to similar designs of other companies. There are also additional considerations. For example, reducing or eliminating back pressure is a key element in the design of new suppressors. Also, there is evidence that muzzle brake and flash hider designs affect rifle operating pressures differently when removed. Unfortunately, I’ve harassed my friends in the suppressor industry enough for now, so this discussion will have to wait for another time.