By Sam Hoober, Alien Gear Holsters
A relatively recent trope for guns kept for home defense is the idea of adding a suppressor to home defense guns. This is picked up steam in recent years as more people started building or buying short-barreled rifles and AR pistols.
That bedside 9mm pistol or modern carbine should, according to sentiment, have a can on it. Running a suppressed home defense gun has been selling a lot of SBRs in .300 AAC Blackout in recent years (.300 BLK was designed with that purpose in mind after all) and it makes sense.
By having a suppressor, you don’t risk damaging the hearing of the other people in your house or traumatizing them with it or something like that yadda yadda yadda.
However, this begs a few questions, largest of which is just how quiet are suppressors, really?
And the answer turns out to be a lot less quiet than you’d think. However, they are definitely effective, and it would definitely be a good idea to add one for home defense and any sort of shooting that doesn’t require use of a holster.
A must-have? That really comes down to opinion. Maybe you think so, and if so, awesome. Do it. Maybe you don’t, and that’s fine too, which is something we’ll touch on.
But first we have to take a brief detour: For Science!
First, one of the loudest things on Earth is when an object breaks the sound barrier. A lot of common calibers propel bullets to supersonic (faster than sound) velocity. Anything that travels at supersonic speeds is going to make a lot of noise.
Since velocity of bullets is commonly expressed in feet per second, the sound barrier is at roughly 1125 fps. That is affected, however, by ambient temperature; the hotter it gets, the faster an object has to travel to break the sound barrier.
So garden variety 115-grain 9mm (typically loaded to about 1130 to 1150 fps) is technically transonic, meaning at or close to the sound barrier. Typical .45 ACP (900 fps or less) is subsonic.
5.56mm NATO 55-gr (around 2900 to 3100 fps for typical barrel lengths) is definitely supersonic. Pretty much all rifle calibers are, unless they’re down-loaded for subsonic velocity.
Second, what you need to know about decibels – the unit used to measure sound pressure levels – aren’t linear; they’re logarithmic, so decreasing sound by, say, 5 dB is actually a substantial reduction.
Also, instant hearing damage occurs when you’re exposed to noise levels above 130 to 140 dB, so any attenuation to that noise level or lower mean that not necessarily “safe” but “safer” sound levels have been reached if you have to shoot without ear pro, such as in case of a home invasion.
So back to it.
Just how quiet are suppressors? Typically, they attenuate the noise of a projectile by 20 to 40 dB, depending.
Ammunition To Go did some testing, and unlike a horde of YouTube channels that are apparently run by idiots, they actually used a decibel meter. (“It’s quiet guys, just listen to the audio” is literally worthless.)
Sound levels were recorded using the MIL-STD method for measuring sound. The microphone is 1 meter away from the source, 1.6 meters above the ground, with the microphone at 90 degrees.
Typical 5.56mm NATO and .308 ammunition sound levels are reduced (attenuated) considerably, by (up to) nearly 40 dB. While neither caliber was reduced to “safe” noise levels (OSHA defines that as 85 dB or less) and definitely would still require ear protection to shoot suppressed, suppressors definitely work.
Now, someone might bring up suppressor design.
While it matters to a degree, it may not matter as much as you’d think. Silencer Central tested more than a dozen makes and models with .308 and 5.56/.223 and no suppressor attenuated either caliber to less than 132 dB, which is still unsafe to shoot without ear protection.
Pistol calibers fared about the same; both 9mm and 45 ACP at standard velocities were attenuated by 20 to 25 dB.
Yes, this includes subsonic ammunition. Ammunition To Go tested 147-gr 9mm loads, which are subsonic, and .45 ACP, which is subsonic in pretty much all standard-pressure loadings.
The caliber that benefits most from suppression is, in fact, .22 LR; in both of their charts, .22 LR is attenuated to below 130 dB when fired from both pistols and rifles.
They aren’t the only ones who found similar results. Check out this video from MrGunsNGear:
Nevermind that he’s using an oil filter as a suppressor (which is legal if you get the tax stamp and a threaded barrel adapter for one) but pay attention to his results.
Subsonic .22 LR was attenuated from an average of 154.4 dB to an average of 126.2 dB, and 147-gr 9mm (which is subsonic) was attenuated from an average of 160.2 dB to an average of 133 dB.
But what about those 220-gr .300 BLK loads that people keep talking about?
Still over 130 dB with a suppressor. You might find some combinations of loading and suppressor that brings it lower (the SilencerShop got down to 129.9 dB so that’s, something) but the reality is no matter what gunshots are loud.
So what’s the takeaway?
A few things.
First, suppressors, silencers, whatever you want to call them, don’t make guns magically safe to shoot without ear protection. There may be some magic combination that can maximize sound attenuation, but they don’t really make any gun whisper-quiet.
Subsonic ammunition doesn’t make as much difference as some people say. Granted, the samples above are rather limited, but what’s obvious is that clearly “subsonic” ammunition is barely, if at all, quieter than supersonic.
Sorry folks, but TV and the movies lie to us. Gunshots will always be loud and Sean Connery wore a toupee.
Exposure to any noise louder than 140 dB instantly damages your hearing; those cilia cells are sensitive and excess vibration kills them. And unlike fingernails, they don’t grow back. Most gunshots produce in excess of 150 dB.
Hearing protection only does so much, though electronic ear pro has gotten a lot better over the years. Therefore, the best thing you can do as a shooter to minimize the potential for hearing loss the better, and the best possible thing you can do is add a suppressor.
Do they make shooting safer? Yes. Shooting a suppressed gun with ear protection approaches zero risk for hearing damage. So it is unequivocally better for shooters.
In fact, a can would ideally be on every gun you own that isn’t carried in a holster, and ideally we wouldn’t have to wait for the tax stamp to get them.
With that said, is one strictly speaking “necessary” for home defense?
Again, here we venture into opinion. Define “necessary.”
Ideally, you’d have one, but the reality is that the odds of a home invasion for most people in most areas of the country are very low. Further, most shootings that occur as a result of a home invasion are brief; a few shots fired at most, if any at all.
Will this harm the hearing of anyone in the house? Yes. It will. But it’s very low odds of a one-time exposure. However, one must also suspect that the noise of a gunshot in that instance is going to be a lot less disturbing than OH MY GOD SOMEONE BROKE INTO OUR HOME.
Had one to guess, that’s probably the far more disconcerting aspect of such an event as well as seeing someone shot and/or killed rather than the noise of the gunshot. And a person will also be exposed to noises greater than 140 dB plenty of times throughout their life.
So “necessary”? Strictly speaking, not in the grand scheme of things, but it’s a darned good idea to have them anyway.
Now if we could just get Congress to stop their shenanigans, it would be a lot easier to get them. If they’re serious about making guns safer, that would be one of the first steps.
Sam Hoober is a Contributing Editor to AlienGearHolsters.com, a subsidiary of Hayden, ID, based Tedder Industries, where he writes about gun accessories, gun safety, open and concealed carry tips. Click here to visit aliengearholsters.com.