Hearing safe SBR

[BassFlats&Beyond]

Pretty soon I’m going to get either a DD mk18 or a PWS mk111mod2. Whichever I go with, it will be a dedicated suppressor host. I don’t know much about suppressors or sbrs. I’ve heard that there is no way to make a 556 hearing safe. I’m really leaning towards a dead air sandman s. I would love to get some input from the more experienced dudes. Will the mk18 be really gassy? Will the piston pop from the PWS be too loud. It there a different rifle suppressors setup I should be looking at?

 

[JBowles]

Nothing with super sonic bullets is going to be hearing safe.

 

[Yondering]

If you use the gun as-is and mount a suppressor on it, any SBR 5.56 will be really gassy. However, if it's a dedicated suppressed rifle (i.e. never used unsuppressed) I'd want to install either an adjustable gas block or a reducing bushing in the existing gas block. That way the gas can be tuned for suppressed use and will only be a little more gassy than an unsuppressed rifle.

As for sound when suppressed - expect it to be right on the edge of ringing your ears a little. About like a 16" 10/22, or slightly louder. It can be significantly louder than that when overgassed, which it will be when you receive it.

 

[Dpvaz56]

Subsonic 300BLK is your best bet for a hearing safe SBR that isn’t a 22LR

 

[BassFlats&Beyond]

Does a piston system like PWS offer enough advantage over a DI mk18 in terms of gas management? PWS also comes standard with an adjustable gas block. Supposedly Daniel defense has reduced the gas port size on mk18s made after 2017.
Hearing safe might be a little optimistic. I have a home range, and I’d like to not piss off the neighbors as much as possible. I’d also prefer to not give my wife permanent hearing damage if I need to touch on off inside.

 

[Tuukka]

Not too many quality suppressor manufacturers talk about hearing safe or guarantee of that.

More like significantly reduced risk of permanent or temporary hearing damage, which is quite accurate as on 5.56 for example we are reducing the SPL at the shooters ear from 155-165 dB down to c. 135-142 dB ( depending on action type and barrel length etc. )

The U.S. MIL-STD 1474D indicated an unlimited number of exposures for impulse noise below 140 dB. Here in Europe, the EU work health regulations state 137 dB ( C peak ) as one level for impulse noise.

Regardless, it is very smart to suppressor rifle calibres, not only to protect your hearing but for the other benefits as well.

Best Regards!

Tuukka Jokinen
Ase Utra sound suppressors

 

[Nate Osborne]

As far as your comment about other rifle or suppressor set-ups to consider. With your intended goal of a suppressed only rifle, you may want to look into a gun that is gassed to run with a suppressor on all of the time.

Check you Sionics barrels. They have two 11.5" barrels for suppressed use. The RGP (reduced gas port) barrel is designed to run full power ammo unsuppressed (barely), but is optimized for suppressed use. The ERGP (extreme reduced gas port) barrel has an even smaller gas port fur running suppressed only, and although they say it could run without a can, it was never intended to, and is not recommended.

Another option if you are wanting a different barrel or barrel length would be the black river tactical gas block inserts or gas tubes. You can pick your barrel, then work with them on a specific size that is small enough to run with the can you use and not be overgassed.

If you are wanting a suppressed only rifle, I would avoid the adjustable gas blocks etc. as they are another potential failure point that really isn't needed for your intended project, in my opinion.

Also, I would suggest for most applications staying with at least an 11.5" barrel, possibly even a 12.5." They are usually more reliable in different conditions and with different ammo, as well as giving you better performance out of most ammo. As always your intended use makes all the difference in what equipment you want to use.

 

[nightchief]

I kinda jumped into suppressing my SBR and though I did a fair amount of research, I realize I really should have done more, to understand the relationship of gas port size, buffer/action spring, and barrel length. Would have saved me time and especially $$$.

I would second what Nate89 says about getting a properly gassed barrel to run suppressed. Is a 10.3" barrel a requirement? I have an Sionics RGP I'm running with an SF suppressor and it runs well, though I still get a fair amount of gas to the face when shooting in multiples. I shoot it mixed, about 50/50 sup/unsup, so its something I live with. If I were going for 100% suppressed, I would look for a barrel gassed for that purpose.

 

[3-7-77]

I have a 11.5” Sig MCX with a Sig SRD556 can and a home built 10.5” AR with an adjustable gas block and Silencerco Specwar 556k can. Both are relatively comfortable at the ear without hearing protection for a mag or so and neither is gassy. Are they “hearing safe?” No, but that’s probably as close as I can get with a suppressed 5.56 SBR.

As far as piston pop, I don’t notice it on my 11.5” or 16” MCX shooting suppressed. I don’t have any experience shooting any other piston guns suppressed, so I doubt that’s helpful to you.

If you’re wanting a DI SBR without gas to the face an adjustable gas block or Sionics reduced gas port barrel will be a must.

Edit to add: This may be an anomaly, but on my 8.5” 300 blackout, I get gas to the face with my Omega direct threaded to the barrel, but not at all when I mount it using the muzzle break.

 

[Arete]

In my experience with a 10.3 with a .073" GP, also a 10.5 and 11.5 Colts, all suppressed with various cans, the Gemtech Suppressed Bolt Carrier makes a big improvement with the gas to the face.

So much so, that I bought 2 of them.

 

[Yondering]

In my experience with a 10.3 with a .073" GP, also a 10.5 and 11.5 Colts, all suppressed with various cans, the Gemtech Suppressed Bolt Carrier makes a big improvement with the gas to the face.

So much so, that I bought 2 of them.

These type of bolt carriers do help a lot, and are a good idea if you intend to run both suppressed and unsuppressed. However - I suggest the Bootleg adjustable carrier instead of the Gemtech, because it can be adjusted through the ejection port (no disassembly) and has 4 settings instead of 2.

(To be fair to Gemtech, they were the first to market this sort of bolt carrier, but a few other companies have come along since then and improved on the idea.)

 

[Arete]

Yes, a friend has the Bootleg carrier (it's one of the more recently made models, IIRC it has the notches for the fwd assist) and he likes it, although he reports there isn't a significant difference between the gas settings. He's using a BCM 11.5 with a SC Omega can.

 

[ggammell]

i just ran my Gemtech SBC and can for the first time last week. There is a significant gas to face difference and noticeable but not astounding change in recoil feel.

 

[Arete]

Correction: The mentioned 10.3, but also 10.5 Noveske, and several 11.5 Colt 6933s.

 

[Gypsy EDC]

Pretty soon I’m going to get either a DD mk18 or a PWS mk111mod2. Whichever I go with, it will be a dedicated suppressor host. I don’t know much about suppressors or sbrs. I’ve heard that there is no way to make a 556 hearing safe. I’m really leaning towards a dead air sandman s. I would love to get some input from the more experienced dudes. Will the mk18 be really gassy? Will the piston pop from the PWS be too loud. It there a different rifle suppressors setup I should be looking at?

PWS has an adjustable gas block with a suppressed setting. Gas vents forward of the receiver rather than in your face. I prefer my pws mk110 over the bcm recce 11.5 my buddy has by a significant margin. Incidentally tried the adjustable bootleg BCG mentioned earlier in the bcm and it was just kinda meh...

 

[Yondering]

PWS has an adjustable gas block with a suppressed setting. Gas vents forward of the receiver rather than in your face. I prefer my pws mk110 over the bcm recce 11.5 my buddy has by a significant margin. Incidentally tried the adjustable bootleg BCG mentioned earlier in the bcm and it was just kinda meh...

Other than the updside-down flash hider, what are you trying to show us in the pics? Not sure I follow...

BTW, venting gas from the gas block doesn't really do much to prevent gas in the receiver, other than as another way to delay bolt unlocking. Most of the gas in the receiver that gets in to your face comes down the barrel as the bcg retracts.

 

[Yondering]

Yes, a friend has the Bootleg carrier (it's one of the more recently made models, IIRC it has the notches for the fwd assist) and he likes it, although he reports there isn't a significant difference between the gas settings. He's using a BCM 11.5 with a SC Omega can.

If the rifle is seriously overgassed as most are, and you've added a suppressor, I don't think a Bootleg carrier by itself is enough to tame it down. If it's gassed correctly unsuppressed though, the Bootleg carrier makes enough difference to adjust between suppressed and unsuppressed, which is the intent.

 

[Arete]

My amigo's rifle is a BCM 11.5", and, since it's a BCM, I am pretty sure it's has an appropriate size GP (IIRC BCM 11.5's are 0.076"), with a H1.

My 10.3"started as a 14.5" and I had the GP enlarged to 0.073", with a H2.

So, both those rifles are appropriately gassed for unsuppressed.

The GT SBC and the BL carrier both make a big difference on those guns when using a can.

I do not know the size of the GP on the Noveske 10.5, nor the Colt 6933s, but there is a similarly substantial difference when using the GT SBC on those guns, as well.

 

[Gypsy EDC]

Other than the updside-down flash hider, what are you trying to show us in the pics? Not sure I follow...

BTW, venting gas from the gas block doesn't really do much to prevent gas in the receiver, other than as another way to delay bolt unlocking. Most of the gas in the receiver that gets in to your face comes down the barrel as the bcg retracts.

You're right you don't follow...

The Triad mod 2 flash suppressor (indexed correctly btw ) wasn't the point of the picture. Right under the tail of the surefire is the adjustment point for the gas block (can be easily adjusted in the field with a 556 round).

Gas isn't vented from the GB, its vented from the gas tube down towards the barrel forward of the receiver (1st pic).

As far as the amount of gas coming back down the barrel vs from the gas impingement system it's simply less gas in the face & less shit in the chamber running a piston...

 

[Yondering]

Thanks, that makes more sense with the explanations of what we're supposed to see. What is the second pic showing us?