How quiet is .300 AAC Blackout suppressed with subsonic ammo?

[Aim1]

Wondering how quiet this is when fired out of a bolt action rifle with a minimum 11" inch barrel. Is it like only hearing the firing pin hit the primer if using a bolt action rifle? If someone was standing next to the rifle when it is fired how far away would they have to be where it would almost be impossible to hear? How close to Hollywood quiet (fake) is it?

 

[Ed Ames]

It's about like a really loud but extremely short rock concert.

 

[Telekinesis]

You're probably still looking in the 125-130dB. Think really good 9mm suppressor shooting subs, or maybe an older .22 suppressor on a pistol.

As far as someone hearing it, that depends on a LOT of factors like environment (heavily wooded vs open fields) and ambient noise. If you change your requirement from "distance to not hear it" to "distance to not recognize it is a gunshot" your distance will drop dramatically.

 

[redbullitt]

It will sound like an airgun in most cases, a nice airgun lol. You will assuredly hear more than a firing pin drop... that is a very optimistic assertion in any case.

Longer barrel has a very noticeable effect on how loud it is, as do the powder used and how much of it. A closed action is a good deal quieter than a semi auto. Faster powders tend to be quieter, and are an option in the bolt rifle. A slower bullet, say 800 fps vs 1000 fps can make a difference as well with less bullet noise whipping through the air. Other things like moisture can be added to some suppressors to help make them quieter, but this depends on application.

As far as hearing the shot, that is hard to say. One isolated shot will probably not be noted as a shot by most folks, say in a hunting scenario. On game animals at distance they tend to pay very little attention in my experience. Videos of suppressed shooting tend to be garbage for comparison... it never sounds right and seems to be a poor way to judge how much sound you are really making imo. Best way is to actually see and hear a few if you can.

The rifle with 11 inches of barrel will be louder than you like, guaranteed. Bring that length up to 18 or 20 inches you you will be much happier at the expense of that nice handy little barrel.... Gotta figure out and focus on what you want the rifle to do. If you try to make it be quiet AND super short you will probably be unhappy with the results as it will be a compromise rifle. I have a short handy ar15 in 300blk with a 10 inch barrel. VERY handy, and quiet enough for its purpose. My other rifle is a 16 inch 300blk bolt action. Not nearly as handy, but much quieter. 2 goals, 2 rifles.

 

[Jeff H]

Listen for yourself. The action is louder than the shot.

 

[Elkins45]

Videos are not particularly useful for judging silencers because of the way the camera compensates and "averages" audio signals. It makes loud sounds quieter and quiet sounds louder.

Also, an AR is a loud action because of the gas dump inside the receiver.

Here's good way to think about it: a good silencer reduces the noise about as much as a good set of earmuffs.

 

[Justin]

Loud but not painful.

As opposed to suppressed .223, which is loud and slightly painful.

 

[Havok7416]

Videos are not particularly useful for judging silencers because of the way the camera compensates and "averages" audio signals. It makes loud sounds quieter and quiet sounds louder.

Also, an AR is a loud action because of the gas dump inside the receiver.

Here's good way to think about it: a good silencer reduces the noise about as much as a good set of earmuffs.

This is basically it. The best will get the sound down to a manageable level, but it's still in the threshold for damage.

 

[Aim1]

This is basically it. The best will get the sound down to a manageable level, but it's still in the threshold for damage.

Strange. Other people have said things like all you hear is the firing pin, the brass hitting the floor, and someone else saying that it was so quiet that they worried about hearing the buffer spring in his stock.

 

[Elkins45]

Buffer spring in the stock of his bolt action?

A sealed beach 22 with subsonic ammo is about the only silenced firearm that approaches that level of quiet.

 

[Havok7416]

Strange. Other people have said things like all you hear is the firing pin, the brass hitting the floor, and someone else saying that it was so quiet that they worried about hearing the buffer spring in his stock.

Even the quietest rated suppressors only bring the sound down to 119 db *claimed* for .300 Blackout. It may be quieter or louder based on how they set up their test equipment, but that's still extremely loud. It just happens to be relatively quieter than a gun fired with no suppressor. Sounds around 70 db and lower are regarded as safe for hearing (unprotected), so it would still have to be reduced substantially to get there.

Now, if you add good hearing protection to the claimed reduction, you might get the sound down to 90 db or so. Definitely quiet and you will likely hear the gun operate and most certainly brass hitting the floor. Heck, I can hear brass when I fire my guns anyway.

 

[Thunderchicken]

I have never fired a gun with supressor, but the comment about subsonic .22 reminds me of a story. This rabbit was eating plants in my grandmother' garden, and one night it was out on the neighbors' driveway when I got home from work at around midnight. I slipped a CB cap into my single shot .22, took aim from around 80 feet, and let fly. Twenty year old eyes are a lot different than mine today. It didn't run, and the round was really quiet, but I figured that if I couldn't hit it with one shot I didn't need to keep trying.

Next morning, it was still sitting in the driveway and the neighbor told my grandmother "it must've just died there." I was impressed and told my cousin about the James Bond-level stealth of the CB cap. A year or so later he had a bunny situation at his house and decided to try one to dispatch it. Except he had a four inch barrelled revolver. He told me he touched off a round in his back garden (he had houses five feet to each side of his place) and, in his words, "a six foot ball of flame erupted from the end of the barrel and it sounded like the New Jersey shelling North Vietnam." Apparently barrel length had had a significant moderating effect.

Funny, I haven't fired a CB cap since then. I wonder if they're still available.

 

[hq]

A properly suppressed subsonic round of any caliber will create a "plop!" sound from the barrel and an audible hiss of the bullet in flight, providing that the powder is fast enough and gas pressure at the muzzle is sufficiently low for the suppressor to muffle the bang completely. The noise level depends on the caliber and bullet shape. The click of the firing pin is audible mainly on bolt and lever action rimfire rifles when the action is close to shooter's ear and tip of the muzzle a couple of feet away. A pellet gun is a fairly good analog and the overall sound signature can be recognized as some kind of shot being fired within approximately 100'.

For best results it's advisable to experiment with handloads using very high burn rate powders, use a high-volume suppressor of modern (late 80's or newer) design and if the gun in question is semiautomatic, the heaviest bolt/buffer and most restricted gas valve/orifice that will still allow the gun to function reliably. A thoroughly optimized combination can be incredibly quiet.

 

[jmorris]

The only ones that I have that are "Hollywood" quiet are manual loading single shot with subsonic. Actually the sounds they dub in for "silencer" equipped firearms are louder that some combinations.



At least until I finally stumble across a Kricotronic but I haven't seen one since the '80's.

The larger the bore diameter the more can I seem to need but I can shoot a 458 socom suppressed off my balcony no not wake up my wife.

 

[greyling22]

I have sensitive ears. Not great hearing, but loud sounds hurt me easily. To me, I can fire blackout subs out of a bolt gun with a good can and not flinch. Supers hurt some and I wish I was wearing some foam plugs. 9mm subs in a semi auto I can shoot without plugs, but it would be more comfortable with them. With supers I need plugs. With a 22, firing subs, you get Hollywood quiet. With supers, I can shoot without plugs, but if I'm going to shoot much I want some. With a 223, I wear plugs and muffs. If it is suppressed, plugs alone are fine.

 

[JeffG]

Here is my Savage Hog Hunter with 308 subsonic handloads. Gemtech Dagger suppressor. Bullet speed about 950 fps, 180 gr Sierra round nose. Most likely this is going to be comparable.Compare the sounds against the bolt working and the brass hitting the bench. The last round is hitting an AR500 metal target at 25 yards.

 

[cdb1]

My FFL has a 10/22 with an aftermarket suppressed barrel. The suppressor is integral to the barrel and is not pinned or screwed on. The time I shot it I didn't even check to see what ammo we were shooting but I bet it was sub-sonic. It's the only suppressed firearm I've seen in person that sounded as quiet as they do in the movies.

Everything else I've heard was substantially louder than a fart in church.

 

[JeffG]

My FFL has a 10/22 with an aftermarket suppressed barrel. The suppressor is integral to the barrel and is not pinned or screwed on. The time I shot it I didn't even check to see what ammo we were shooting but I bet it was sub-sonic. It's the only suppressed firearm I've seen in person that sounded as quiet as they do in the movies.

Everything else I've heard was substantially louder than a fart in church.

Everybody turned around? LOL

 

[cdb1]

Everybody turned around? LOL

With giggles.

 

[hq]

It's the only suppressed firearm I've seen in person that sounded as quiet as they do in the movies.

I have a similarly built 10/22. It's very quiet but so is any properly suppressed rimfire; it's impossible to tell the difference between it and any of my other suppressed semiauto rifles and pistols by sound alone. Whenever there's more noise, insufficient suppressor volume in relation to residual gas pressure at the muzzle, poor suppressor design and unsuitable ammo are suspect.