Suppressors 300 blackout sub/super ar suppressor

Maybe check out the Surefire 300 SPS.

If you want quiet subs in an AR, get a RifleSpeed gas control and shut the gas off, cycle manually. Combine that with trailboss handloads and it’ll be stupid quiet. Write your super gas setting down on some painters tape on the stock. Then you can switch back and forth between supers and subs w/o tools.

Trailboss won’t cycle an AR, and suppressed subs that will reliably cycle will be kinda loud…

Man, it’s tough to beat the old Dead Air Nomad L Ti for 300 blk. Some buddies and I got together a while back and messed around with about 15 different cans on 300 Blk semi’s and bolt guns. My old as shit L Ti sounded the best to our ears on both platforms with subs and supers. Off the top of my head, we had a Nomad 30, Nomad Ti Xc, TBAC Dominus, TBAC Magnus, DA Wolfman, DA Sandman, OCL Hydrogen and Hydrogen S, a couple GSL cans, TBAC ultra 7, and a Huxwrx Flow 762 and a couple more I’m forgetting.

We ran these on a 10.5” 300 blk bolt action pistol and my 8.7” AR pistol.

The supers were some garbage I had laying around and the subs were 220 SMK hand loads running around 1,000 FPS through the 8.7” AR. All cans cycled 100% with the AR.

Delicatessen said:

Should have clarified, assuming I want it to cycle subsonically as well as supersonic. I am working on quieting the action with a silent capture spring and either a griffin or kak down/side vent bcg to limit port pop etc. I have 22 etc for bolt action that is very quiet. My question is related to where the semi auto may be the limiting factor vs the suppressor on 300 subs.

My idea of very quiet is roughly in the range of a delayed blowback 9mm subsonic (have a custom Cmmg radial right now). I live far enough out that occasionally it would be nice for coyotes that come in near livestock.

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The action alone (no ammunition. Just slamming into battery) can meter as high as 130 dB…

My 300sps and nomad 30 make subsonic 300 very quiet; yes, the action cycling takes away from the epic "shhhhh". Those are usually on my bolt 300 uppers.

I have found the CAT ODB to be a good option too, with less blowback--this is important to me and a high flow can like HUX isn't ideal. Some rapid fire for a few 20 and magazines got the ODB Ti version to (only) mid 300 deg.

I just got back form the range shooting a DIY 300 blk using Noveske's 7.9" 1:7 and the ODB above. It has the KAK down vent carrier, which I used more for less gas out the ejection port than any dB reduction. It cycled and locked backed on Magtech 200gr, American Eagle 220, and Sig 220 but only cycled and didn't lock with Fiocchi 220. Hornady Black is finicky (I think it's got a standard carbine spring and H buffer... but would need to double check).

Im also trying the strike Industries adjustable gas block bc I think the collar adjustment is intriguing and doesn't require an tool.

I am using a Thunderbeast Ultra7 on my 300 Whisper/Blackout M-16RR. It is plenty quiet even when I use AA1680 for a powder which is on the louder side of things.

Semi autos are not that quiet compared to bolt guns. No way around it.

Checking numbers pre-Garmin...

My 300BLK SBR runs an Otter Creek Labs - Hydrogen L 7.62 and I am extremely pleased with the quiet factor! My SBRs all run JP Rifles Silent Capture Springs and aside from a small amount of buffer spring noise (you can't get away from it 100%), my 300BLK is easy to shoot and does not require hearing protection (though some will say you should always wear hearing protection...).

Delicatessen said:

Should have clarified, assuming I want it to cycle subsonically as well as supersonic. I am working on quieting the action with a silent capture spring and either a griffin or kak down/side vent bcg to limit port pop etc.

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According to Griffin the new bcg works based on gas tube length. The longer the tube the better it works.

I have personally tested it and yes it is correct (obviously). On a short 300blk there are no sound gains between a regular bcg and the new one. Again, the effectiveness is going to depend on the gas length on the rifle.

Another factor is the ammo makes a massive difference in how quiet things get. Not all subsonic ammo is created equal.

I don't know if you reload or not but for me I have had a long term pet project to create the quietest load possible. I don't mean little pud loads or rabbit farts, but the powder and other components combo makes a really big difference.

I only tell you this because ultimate quiet includes more than just the can. I only have a few 30 cal cans but in theory you can make a mediocre can perform substantially better (with good ammo) than you can make a great can with bad ammo.

If you want another can by all means get a good one. For me the length and weight of the can are more important than just pure DB. Silly quiet is excellent but for me at this point all around use is a better idea.

I’ve shot a blackout pistol 8” barrel and Rex MG7 with Ammo Inc, Magtec and Hornady SubX all subs. Mostly action noise as mentioned before, sounded about like a hard hand clap when shooting no ear pro. Probably even less from 10 feet away. Honestly not sure a bigger can would do much more on an AR with subs, Rex is around 5.75” iirc. I think you’d have to try the same can and ammo on a bolt gun or gas off on AR to hear the difference between a K can and full size etc but I’m just guessing.

Nomad Ti