Practical Suppressor Basics
Practical tips for the much maligned muffler of gun noise
BY DOC SPEARS
If you check my blog from last week, I ma
de a prediction as to whether any of the pro-2A provisions would actually making it into the One Big Beautiful Bill. As we did not get the big win of removing suppressors—erroneously referred to as “silencers”—or short barreled rifles from the National Firearms Act, my pessimism was proved partially warranted, and partially debunked.
The $200 tax stamp fee was successfully removed, solely due to the persistence of a few heroic members of the House, but the registration for those items still exists.
It’s not near what we’d hoped for.
However, here’s the silver lining to that cloud; with the removal of the fee, there stands a very, very strong legal challenge to the legality of the registration required by the NFA. Because it’s already recognized that the NFA’s basis lies in it being a tax, if there’s no longer a tax, then a registration can’t be constitutional! At least, that’s what the 2A attorneys fighting on our behalf believe, and lawsuits are underway to challenge the very constitutionality of the NFA.
Baby steps. Finally.
If the OBBB becomes the stepping stone to repealing the NFA, we’ll look back on the Byzantine mechanics of how this bill was brought to the president’s desk not with contempt, but as a masterful maneuvering against those who want to deny us our 2A rights.
In the last Tip of the Spear I explained the NFA, made some prognostications, and ended with a promise to discuss practical aspects regarding the selection of your first suppressor—which I’ll call a “can” from here on out. I get frequent messages asking my recommendation on who makes the best can, which one offers the greatest noise reduction, which is most accurate, what mounting system I prefer, etc., etc.
I checked just before sitting down to write this; I have guns wearing cans made by (in no particular order) Surefire, AAC, Thunder Beast, Desert Tech, LaRue, and a few others made by companies no longer in business. They live on a variety of guns; precision bolt guns, precision gas guns, carbine and pistol-length ARs, and .22 and centerfire pistols. I have cans that attach by each of the three ways to do so: direct thread, thread-over-brake mounts, and the quick detach (QD) systems (more about all those toward the end).
To begin with, my consensus based on a few decades of personal use and further experience as a trainer with virtually every make and model of can used by students is this; they all do well, and not one of them is particularly superior than any other in terms of practical noise reduction.
I’ll explain.
(Forgive me if I don’t go into an in-depth discussion of the decibel (dB) scale, or the standardized means by which sound output is measured at the muzzle and the shooter, or any of the technical stuff. The info is out there on virtually every suppressor manufacturer’s web site, and you should read it.)
It all comes down to environment.
If you’re shooting on an open range, any can rated as ear-safe will provide a hearing-safe environment for the shooter, and for everyone else on the firing line. I regularly run firing lines where everything from 14.5” barrel M4s to 26” barrel .338 Lapua Magnums are being shot—all sporting any of the variety of cans I’ve discussed above—and no one on the shooting line or behind it needs to wear any form of hearing protection to be comfortable.
The amount of fatigue and fuzziness experienced from having your brain-rattled all day by gunfire is very appreciable. Once the military caught up to the civilian world and started issuing cans across the board, my life got better, quickly.
Understanding all of that, I have to explain that what qualifies as “ear-safe” changes drastically when we add structures like walls and roofs to the shooting environment.
If the firing line has a covered roof, the reflection of sound and muzzle blast means you’ll still need to wear hearing protection, like ear plugs or over the ear muffs. You receive much, much less decibels than without a can, but the noise and reflected blast is not only sharp and unpleasant, but damaging to the bare ear. Even sub-sonic velocity rounds (less than about 1000 feet per second) can amplify to painful levels if you’re shooting under cover of a metal shed roof.
Cans drastically reduce the decibel output as well as the muzzle blast, but if you’re training in a shoothouse, the walls will drastically bombard your ears with what leaves from even a suppressed muzzle; so wearing hearing protection is a must. If that shoothouse also has a roof, to avoid ear damage you’ll need to double-up and wear both earplugs and over-the-ear protection.
I ran a shoothouse class some years ago for an agency that had nothing but short-barrel 10.5” ARs without cans and instead, all wore muzzle brakes that created blast intolerable to anyone but the shooter, even outside. Despite taking the precaution of wearing double ear-protection after four days of running teams through the shoothouse, my tinnitus went from occasional, to permanent. (If I were emperor of the world, my first decree would be that all short barreled rifles have cans welded on.)
Suppressors are safety devices.
A handful of years ago at a .50 caliber Hard Target Interdiction course, the Army sent a team to try and quantify the amount of pressure damage we received in hopes of establishing guidelines to identify exposures leading to traumatic brain injuries. (We do the same with explosive breaching training—another environment where blast and noise can scramble your gray matter). Each morning our vitals were taken, blood samples drawn, and at the end of the training day the pressure transducers we wore were collected.
The result; the team readily established how even in open air shooting environments, the .50 cals surpassed thresholds for exposures that caused not just hearing damage, but TBI. And when firing from within structures—environments common to snipers—even the .50 cals with the then new Barrett suppressors—the thresholds for TBI were exceeded. By large amounts.
Don’t ask me why I’m irritable and speak loudly and sometimes drool (just kidding about the drooling part).
Suppressors are safety devices. But they don’t provide an ear safe experience in all environments. Which is why agonizing over the choice of a manufacturer whose can lists a noise reduction rating that’s a few decibels better than another manufacturer, it doesn’t make as much practical difference, IMO. If you buy a good can, you’ll be just fine, regardless of whether another choice was a little better in the noise department.
Cost is always an issue. And yes, like everything, you get what you pay for. High dollar doesn’t always mean better, but it usually does in the firearms world—especially in terms of durability. I had a somewhat inexpensive can that in completely normal use shot a baffle loose. The manufacturer cut and rewelded it, and they’ve since gone out of business. I’ve never had the same happen to any other can I own.
Mounting options: If you look at the picture above, on the left are two precision bolt guns. The top example has a direct thread mount. Most any rifle can now be had from the manufacturer with a threaded barrel that will accept a suppressor. All you do is screw on your new can, and you’re set. Easy on, sometimes easy off (I’ll explain in a second.)
Any suppressor mounting system can loosen as you shoot, so it’s necessary to check frequently to make sure it’s on tight. A rule for use with any can: the one time you don’t check to make sure it’s properly tightened, that’s the time your can is loose. I’ve seen cans fly down range. The can was removed for cleaning, but the shooter got hurried, failed to check that it was restored properly back on the muzzle, and with the first shot—off flies the can. Sometimes, without damage, sometimes not.
Make checking the tightness of the can to the muzzle attachment part of your no-fail pre-firing check list, and check the tightness occasionally as you shoot. After removing for cleaning, it may take several tightenings as you shoot before it stays reliably snugged down.
Thermal suppressor covers primarily mitigate the mirage rising off a hot can. The rising waves of heat will interfere with your image in a magnified optic—the same as heat rising off a barrel, and the cover keeps you shooting longer with a clearer image in the scope. A thermal cover gives a surface you can grab to check the tightness of the can while it’s still hot. But if it’s after a long string of fire and you can’t wait for it to cool, even with a cover you’ll probably still want a glove. The slip-on type Velcro suppressor covers will shoot loose, and I prefer the lace-up type, but they must be checked; any of them can slowly sneak toward the muzzle. You won’t notice until you miss a shot, and check to find you’ve blasted a hole in your expensive cover.
The rifle on the bottom left of the picture has a thread-over-brake design. If the threads on the brake become damaged, rather than necessitating a recutting of the threads on the barrel (a process requiring the barrel to be removed from the action so it can go on the lathe), a new brake can more easily be installed. It’s more of a theoretical issue, but it has happened.
The real advantage to a thread-over-brake mounting system—especially as a choice for a precision rifle—is that the face of the muzzle remains extremely clean, whereas on a direct thread suppressor, some caliber choices redirect a lot of the ejected copper and carbon back onto the muzzle, which from a concrete cake around the muzzle, sometimes with detrimental effect on accuracy. This tends to happen with the bigger, faster cartridges, but it’s very specific to a combination of factors. I have at least one direct-thread system where the muzzle has to cleaned occasionally, but never on a thread-over-brake system.
It used to be that the direct thread was the choice of preference for accuracy, owing to its near perfect repeatability when mounting. I’ve come to prefer a thread-over-brake; the muzzle face remains spotless, the barrel threads can’t be damaged, and it’s just as accurate a mounting system. In practice, there’s no substantial difference between the two choices, and I have them both on many guns.
It’s very possible to purchase one suppressor for use on many rifles of different calibers. Choose a suppressor for the largest diameter caliber you’ll use, have the same mounting system on all other smaller caliber rifles, and use that single can on all. The loss of decibel reduction on the smaller calibers by using a larger-caliber can is quite negligible. I was an early adopter of this for my switch-barrel rifle systems, where I run a .338 can on all my barrels down to a .264 caliber bore, and they all remain wonderfully ear safe. The military’s Mk22 sniper package utilizes this same one-can-system for its three cartridge/barrel combinations, and is part of the best sniper weapon system our military has ever had.
Carbon will build up on the threads and act like concrete to glue the can to the mount. A copper-based anti-seize should be applied to the mounting threads to prevent that nearly permanent condition, and will need to be reapplied regularly. When a can does seize, the solution is the 2x4 and the red dead-blow hammer pictured above. Lay the 2x4 under the joined section and work radially around the can by using use sharp, rebounding strikes with the dead blow hammer. I said a dead blow hammer. If you don’t know what that is, learn. If you use the hammer from your tool box, you’ll ruin your can. This method will break the carbon fouling apart, and the suppressor can be unscrewed and the threads cleaned.
I have to remove someone’s can using this technique at least once a month. This is a method suggested by many manufacturers like Thunder Beast, and is absolutely reliable and safe, and will save you having to take your rifle to a gunsmith to do the same thing to remove your seized can. You can avoid learning this technique by regularly cleaning the caked carbon fouling off the threads of the mount with a copper brush, then liberally applying anti-seize (the copper grease gets everywhere no matter how careful you are and will stain your hands and clothes, but wear it as the mark of a professional).
Never clean your rifle’s barrel with the can on—if you lose a patch or a brush in the baffles of the can, you’re screwed.
Finally, the M4 pictured on the right has the last mounting option; the quick-detach. It’s another type of suppressor-over-brake mount, but without threads. Because ARs are so “gassy” and dirty, a threaded attachment is less desirable. A small protrusion on the brake fits in a divot inside the neck of the can to provide a consistent index, then the collar is tightened and locks in place—preventing the can from coming off during high rates of fire. A QD can really needs the carbon scrubbed off the brake regularly, and the inside of the can brushed out, or the carbon accretion will lock the can on like a weld. Since it doesn’t use threads, there’s no torquing surface to help remove it. The same technique with the dead blow hammer works, but don’t strike on the QD collar; apply the blows around the smooth barrel of the can nearest the collar.
Traditional dogma is that QD attachment systems don’t lend themselves to superior rifle accuracy, as the return to a precise mounting position is not as perfect as a threaded system. That orthodoxy’s been challenged by many QD systems like that used on the Mk22 sniper system, and I can attest, it’s one of the finest factory produced precision system built; QD can and all.
Though there’ve been manufacturers who’ve made the claim, I’ve never had a can improve a gun’s accuracy. If your rifle shoots about one-inch groups at a hundred yards, the can isn’t going to make it a half-inch gun. Improve accuracy by some small amount? Hang nearly any device off the muzzle of a thin barrel to dampen its motion, and there are often mild improvements. I’ve more often seen cans make a rifle less accurate, which is almost always a result of a DIY (which frequently results in a damaged can—bullet strikes on a baffle or the end cap).
If the gun didn’t come factory threaded, have a real gunsmith do the job, not your buddy with a lathe. A thread-over-brake mount can be installed easily on a factory muzzle-threaded barrel, but the brake has to be timed with shims. If you haven’t been formally trained how to do it, and you care about your rifle and your new can, don’t YouTube it; pay a gunsmith to do the job right.
Cans are safety devices. They save hearing and prevent concussive forces to the brain and are considerate to everyone around you. Many states permit suppressors for hunting, sanely recognizing their purpose is to save hearing. Shooting without ear protection is wonderfully liberating and removes fatigue. A suppressed .22 is a magnificent tool for introducing the sport to any new shooter, especially kids. A can will not make any firearm “silent.” And in some physical environments, even with a can, you may still need to wear hearing protection.
I have higher hopes today that we near sanity and that someday soon anyone can own a suppressor without begging the approval of a bureaucracy whose purpose is to see you labelled a criminal.