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

Some flow cans may not have enough backpressure to cycle subs, FYI. Rex MG7K, DDC Enticer S Ti, and A-10 7.62 all work well for me.

I plan to try my CAT ODB on the one I am building.

I am running an older Sog 762Ti QD on my MCX Virtus and a few other blackouts. Higher back pressure cans will always control flash and sound report better. However, the powder choice has a huge impact. CFE223 is much flashier than Varget. It's why the military ammo has flash reducing components. From my understanding, low back pressure cans aren't as great with subs and some may not cycle with a gun if the gas port is conservatively sized.

For 300Blk and hand loading subs, VV N120 is an amazing powder. It burns very clean and is night and day less dirty than CFE Black or other more common powders. It still produces enough gas to cycle the action and has very little flash. Runs great around 11gr with 220 subsonic. Hand loading with the right powder may have as much of an impact on how loud or flashy the shooting is. Good food for thought.

Also N220 runs great with an Omega9k. That can isn't as quiet but it's super compact. And can run supers. And is full auto rated so it's built well.

This is one of the reasons I’m adding a CAT ODB to my collection. I don’t have it yet, but from what I’ve read from Pew and other places it’s the perfect blend of low back pressure while still retaining excellent suppression on subs.

I have tons of subs/super videos on AR's and bolt guns on my youtube with many different cans. Feel free to check it out.

I have both piston and DI 300 blackouts, 9" barrel on the piston and 8" barrel on the DI. The DI uses a captured system from Unrivaled. I use their captured buffer on several gas guns and they make both a standard and lightweight buffer for use with lightweight BCG's. Really good stuff that actually works.

With the DI guns I've built, a lightweight BCG has been the ticket along with an adjustable gas block (Riflespeed for the win) in terms of reliable cycling. I generally have a four click spread on the Riflespeed gas block between supers and subs. I've never really had a problem cycling any subs, let alone supers, with my hand loads using several powders. CFE Black is dirty as it produces a ton of gas and it'll force anything to cycle so it's dead reliable. I do use Vihtavouri N110 which as others have said, is clean-burning and is good to go while being faster burning than the VV120 and doesn't need as high of pressure for optimal burn rate. I don't find either of those to be "noisy" powders like say Lil' Gun or H110 (for subs) and both work for supers although the VV is better for supers than 300 Black and I'll take H110 over both.

My piston gun is all proprietary so there's no swapping anything out really. Still, it'll cycle factory Hornady 190 grain subs even in forced reset trigger mode at full auto rates of fire on the lower gas setting with any suppressor I currently have from full flow through to standard baffle cans.

In terms of cans and function, I have no problem with function on any of them on either rifle and I have everything from the Flow762Ti, to the HDQD762Ti, to a Diligent Defense Enticer S. In the middle I have a few Radical Defense cans which aren't ultra low back pressure like the Hux but not as restrictive as the Diligent Defense Enticer S (insert any standard baffle can here). I have the short and long versions of the RD cans.

In terms of perceived noise, I can't tell much difference between the Hux and the Enticer S. The Radical Defense CS3 is allegedly made for 300 blackout and I've shot it, no ears. Isn't horrible but I wouldn't do a mag dump or range day without ears. I've also been next to someone shooting subsonics with the Hux 762 Flow Ti and I was actually impressed at how good it sounded. But I was also on his left side, non ejection port side. My CS3 is the more robust Haynes 282 super alloy version so it's the permanent fixture on my go-to piston 300 Blackout as it'll take anything I throw at it whether it be supers or subs. I have no doubt the LS3 is likely quieter since it's about 2" longer but I can't tell with ear pro.

Bottom line, the port pop is going to be the limiting factor at the shooter's ear. Piston guns probably have less port pop but mechanically seem louder to me. Downrange, a standard baffle can is going to be better but forget about shooting quickly. I've done that with my piston gun and the Enticer S in semi-auto and after about 20 rounds, I couldn't breathe. Indoor range so I'm sure that didn't help. I'd stay away from anything Dead Air just do to all the problems they've had, continuously, over the years. The Diligent Defense Enticer L in Ti is every bit as quiet as the Dead Air cans and cheaper to boot.

I have the relatively new Hux Flow 9K Ti in jail and I'm interested to see how it'll do mostly as it's full auto rated with 300 blackout and ultra light, under 5oz. direct thread. I'll mainly be using it on a ported 9mm PCC SD with radial-delayed BCG system which, if you want Hollywood quiet (and not suppressed 22LR) is the way to go.

A buddy has the full size KAC .30 low back pressure can. It's the quietest .30 cal can on 300Blk subs I have ever heard. It's insane.

Currently I am using a YHM Resonator 2 tucked under the hand guard on a 9" barrel. The action is the loudest part, but it is still hearing safe and from more than a few feet away you can't hear squat. Before changing it to a tucked suppressor I used an SF 300SPS, that may have been marginally quieter but I honestly couldn't tell you which was which without looking.

Shooting at night under NODs, some friends were around 15' away from me and they couldn't tell where I was shooting from. They just heard the impact on the steel at 100 yards. They said it was the freakiest thing they had ever heard/experienced. Just the steel smacking with zero idea where I was at.

I think a lot of people get wrapped up on port pop and the action because it's obviously right in the shooters face. But get a few feet away and you won't hear it.

I threw my TBAC Magnus on my Desert Tech 300 Whisper/Blackout boltgun.

Hollywood quiet baby. Now it stays on that rifle.

Here's my 300BO (8.2" barrel) with OCL Hydrogen L. Has a Law Tactical Folder, so it fits into my Vertx Gammut backpack for easy carry! EXTREMELY quiet...shooting 190gr Sub-X, 200gr S&B FMJ's, Halworx 200gr REX, SteLTH 220gr or Range Dynamics 220gr subsonics.

Man, it might seem like I'm scraping the bottom of the barrel here, but the YHM R45 is a killer can for 9mm and 300BO. I also have an R9 that performs well, just not quite as well. They are cheap, have good signature reduction and actually cool pretty quickly.

TonyAngel said:

Man, it might seem like I'm scraping the bottom of the barrel here, but the YHM R45 is a killer can for 9mm and 300BO. I also have an R9 that performs well, just not quite as well. They are cheap, have good signature reduction and actually cool pretty quickly.

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YHM, when you want a lot, but don’t want to pay a lot…

I have been running a Deadair Nomad on my Noveske 300BLK for 2 or 3 years. I have an Abel Biscuit on it now but haven't shot it yet with the Biscuit but plan on it either tomorrow or Sunday. I was very happy with the Nomad but thought I'd try the Biscuit and possibly switch the Nomad to another rifle.

C130 said:

I have been running a Deadair Nomad on my Noveske 300BLK for 2 or 3 years. I have an Abel Biscuit on it now but haven't shot it yet with the Biscuit but plan on it either tomorrow or Sunday. I was very happy with the Nomad but thought I'd try the Biscuit and possibly switch the Nomad to another rifle.

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Curious how the biscuit works! Let us know.