You’ve probably seen or heard a lot about Suppressors if you’ve been reading about precision rifle shooting! They’re a pretty popular item. I talked to Don the other day after he fired one and his thoughts mirrored my own after I had tried one the first time; “I never want to shoot unsuppressed again!” I’m sure you’ve seen a suppressor in the movies but how they behave and work in reality is another discussion. The discussion I intend to have with you today! We’re going to talk about how a suppressor works to suppress the noise of a projectile as it moves down the barrel and off toward the target.
How A Suppressor Works
The easiest way to think of a suppressor is like the muffler on a car. The idea is to suppress the gas and noise that come shooting out of the barrel along with the projectile when you fire a rifle. Which brings me to another quick point, these items are suppressors. Don’t call them silencers. That’s like calling a magazine a clip and it instantly revokes your man card. When firing a rifle you generally have two to three sources of noise. If the rifle is a bolt action you only have to contend with the sound of the high pressured gas propelling the bullet and the crack as the bullet breaks the sound barrier. If you’re shooting a semi-automatic rifle you also have to content with the mechanical noise of the bolt carrier cycling rounds through the rifle.
There isn’t much you can really do about mechanical noise and if you’re shooting bolt action it doesn’t really matter because there isn’t any noise till you manually run the bolt. That just leaves you with the crack and the expanding gasses. You can’t suppress the crack at all so unless you are shooting subsonic ammunition that part you have to live with. It’s also why you should raise an eyebrow when people say a suppressor is “hearing safe.” Anything over 85dB can cause damage that is both permanent, and cumulative. I shoot suppressed but I always wear earpro because of the crack.
What about those gases? This is the main element you can do something about. By attaching a suppressor it helps slow down, trap, and quiet down the noise associated with those expanding gasses.
Most suppressors are a system enclosed in a steel or titanium tube. This is where the “can” nickname comes from. Within the can is a system of funnels that are called baffles. The baffles are funnel shaped with the spouts leading to the next baffle in line progressing towards the muzzle of the rifle. I said that correctly, the funnel shaped baffles face the opposite direction of how a funnel typically works. The idea is that as the gas exits the muzzle and expands it gets trapped in these progressive baffle chambers. The hole in the funnel shaped baffles allows the bullet to fly through the opening in each baffle and out the end of the suppressor.
If you’re thinking how precise these must be made you’re correct. While the quality of the can is important an often overlooked issue is the quality of the muzzle threading. An inexperienced person or a company doing subpar threading might thread the muzzle of a rifle barrel so that it’s concentric with the outer diameter of the barrel. You couldn’t make a bigger mistake. The threads need to be concentric with the bore of the barrel so that when you screw the suppressor on all the apertures in the baffles line up with the bore. If those apertures aren’t precisely aligned you can wind up having the bullet clip parts of one or several of the baffles or even the end cap at the face of the can. This is referred to as a baffle strike. Repeated strikes can damage the can and risk a much bigger issue if the suppressor fails. As you may have guessed, it also jacks with accuracy!
Where does all that heat go? Into the can! Suppressors will heat up with repeated use fairly quickly. They can get hot enough to burn you just by touching them accidentally. This is especially true with steel suppressors being used on semi automatic weapons with high rates of fire. All that heat will start to boil off the top of the suppressor and create mirage in front of the scope. For that reason you almost always see people running a mirage cover on their suppressor when shooting precision rifle. This is a heat resistant material that blocks the mirage and contains the heat so the sight picture isn’t obscured. They also help avoid accidental owwwies when you touch or brush up against one that’s been shot recently.
When you aren’t shooting actively, I recommend you pull the mirage cover back off the suppressor and onto the barrel. This allows some of that heat to boil off and escape. You want the can to cool down when you aren’t shooting it. Overheating a Titanium suppressor can lead to the welds failing. This is just shy of impossible with a bolt action or any precision rifle shooting including semi automatic. Precision shooters don’t tend to hammer away shot after shot unless they’re really bad at hitting what they’re aiming at. Thunderbeast Arms has talked a lot about this because they produce some of the finest Titanium suppressors you can get your hands on. It would take around two full magazine dumps to get a titanium suppressor up to a dangerous temperature. Figure around 50 rounds fired as fast as you could pull the trigger on an AR10 might get you in the neighborhood. Keep your shooting pace below that and you’ll be fine. If you want to rock and roll…buy a steel can that can deal with higher temperatures and rates of fire.
While not a complicated subject, it’s new to some people and it’s definitely a fun topic. If you’ve never shot a rifle with a suppressor on it you’re truly missing out. It’s just one of those things that makes a grown man giggle like a little kid. Suppressors are legal in most non-communist states here in the USA and are very popular in Europe. If you’re interested in the process of purchasing a suppressor we did an article on the topic. Keep in mind there have been some legislative changes since that article was written but it will give you a sense of what’s required. If you have any questions or comments, do so below!