Suppressing 10.5” 5.56

[maroonandwhite]

I recently picked up a 10.5” 5.56 to use as a truck/critter gun and possibly for home duties. I live out in the sticks with no neighbors so it’s nice to have a small rifle ready to go for anything that may come up. Now to the question:

I currently have an AAC 7.62 SD on  .308 and am considering getting a QD flash hider for the 5.56 for double duty. From what I see I’m not sure the suppressor will have much perceived benefit on reducing the possible hearing damage. I’ll use ear pro outside of any bump in the night situations where I don’t have time to put on the muffs. 
 

Second part:  I don’t want to mess with an adjustable gas block. I currently have an F marked block installed with a larger gas port similar to the MK18. I like the fixed sight so I’m also wondering if the gas will be intolerable by suppressing an already over gassed rifle. 
 

My goal is to reduce any permanent hearing damage. If it’s way too much expense, added weight, and overall trouble trying to obtain a minimal result then I’ll hold off. I love the way this thing is balanced without a suppressor. 

[Hozzie]

If it is already overgassed, I think you may have issues.  Being that it is a 30 cal can on a 5.56 it will have a bit less pressure, but probably not enough to not cause issues.  You will get a lot of blowback I would guess.  

I don't think you will hurt anything trying it though and see if it is tolerable.  Or get something like a flaming pig to push the blast forward more.

[Chucktshoes]

This is a possible solution for gas blowback. 
 

https://www.weaponoutfitters.com/ar-gas-vent.html

[Johnny Rotten]

You will still need hearing protection with a 762 can, it will still be loud(er).

[maroonandwhite]

1 hour ago, Chucktshoes said:

This is a possible solution for gas blowback. 
 

https://www.weaponoutfitters.com/ar-gas-vent.html

That’s interesting. Any experience with one?

[Chucktshoes]

Just now, maroonandwhite said:

That’s interesting. Any experience with one?

Nope. It’s a rec from a buddy of mine who swears they’re the tits for a suppressed ar and the only reason for the existence of a forward assist port. 

[maroonandwhite]

Just now, Chucktshoes said:

Nope. It’s a rec from a buddy of mine who swears they’re the tits for a suppressed ar and the only reason for the existence of a forward assist port. 

Worth a shot for the price. Thanks. 

[FrankD]

On 3/24/2020 at 11:02 AM, Johnny Rotten said:

You will still need hearing protection with a 762 can, it will still be loud(er).

Agreed my rugged surge on my 10.5" 556 is still plenty loud.  I wouldn't want to fire it indoors unless I have to, but it is quieter than an unsurpressed 16" gun. 

[my82cam]

If you don't do something to cut the gas back while suppressed, you will beat your gun up.  I run 10.5 with an AAC M4-2000 can on an M16,  if I don't cut the gas back, it cycles at twice the normal speed.  

[Johnny Rotten]

2 hours ago, my82cam said:

If you don't do something to cut the gas back while suppressed, you will beat your gun up.  I run 10.5 with an AAC M4-2000 can on an M16,  if I don't cut the gas back, it cycles at twice the normal speed.  

Do you have a video? 

Its ROF (rate of fire), 650 is the sweet spot, suppressed unregulated is probably around 850-950ish.

 

[my82cam]

oh, I have videos but I can't post them here.  I am not smart enough to post on TGO lol  PM me your phone number and Ill txt them to you

 

Edited April 13, 2020 by my82cam

[Capbyrd]

On 3/24/2020 at 8:45 AM, maroonandwhite said:

I recently picked up a 10.5” 5.56 to use as a truck/critter gun and possibly for home duties. I live out in the sticks with no neighbors so it’s nice to have a small rifle ready to go for anything that may come up. Now to the question:

I currently have an AAC 7.62 SD on  .308 and am considering getting a QD flash hider for the 5.56 for double duty. From what I see I’m not sure the suppressor will have much perceived benefit on reducing the possible hearing damage. I’ll use ear pro outside of any bump in the night situations where I don’t have time to put on the muffs. 
 

Second part:  I don’t want to mess with an adjustable gas block. I currently have an F marked block installed with a larger gas port similar to the MK18. I like the fixed sight so I’m also wondering if the gas will be intolerable by suppressing an already over gassed rifle. 
 

My goal is to reduce any permanent hearing damage. If it’s way too much expense, added weight, and overall trouble trying to obtain a minimal result then I’ll hold off. I love the way this thing is balanced without a suppressor. 

You need to head in to Rossville (just right up the road) and talk to Bruce Swindoll at Wolf River Precision.  I'd bet he could make you some great recommendations.  

[mike_f]

Here's another possibility that might work with your constraints:

The BRT EZTune Gas Tube reduces gas system flow and corrects excessive gas drive from barrels with large gas ports or for use with a dedicated suppressor.

The EZTune Gas Tube replaces the standard CAR length gas tube and requires no modifications or removal of the gas block, making it ideal for barrels with pinned muzzle devices or gas blocks.

After installation, it requires no user adjustments or maintenance.

It is available in several port sizes to meet many small frame AR applications.

This items consists of 1 gas tube and pin.

Installation requires removal and replacement of the gas tube.

Installation is extremely easy and should take less than 10 minutes, start to finish.

https://blackrivertactical.ecwid.com/BRT-EZTUNE-Gas-Tube-Carbine-p103167251

At $55 it's more expensive than the forward assist vent suggested earlier though.  They ask for several parameters regarding how you use your rifle (barrel length, type of ammo, buffer, spring, BCG, suppressor make/model) to determine which gas port size would be appropriate.

I have used gas blocks from BRT, they've been of good quality and have worked well.  I have no experience with these custom gas tubes, however.

[maroonandwhite]

On 3/24/2020 at 12:06 PM, Chucktshoes said:

Nope. It’s a rec from a buddy of mine who swears they’re the tits for a suppressed ar and the only reason for the existence of a forward assist port. 

Circling back around to this. I wonder if leaving the FA out completely would yield a similar effect. I’m sure this piece is going direct the gasses upwards rather than straight out. I’ll try it first without. 

[Capbyrd]

13 minutes ago, maroonandwhite said:

Circling back around to this. I wonder if leaving the FA out completely would yield a similar effect. I’m sure this piece is going direct the gasses upwards rather than straight out. I’ll try it first without. 

Possibly.  I think the opening might be too large without anything in there and so the gas might not actually get out, if that makes sense.  I also think having a hole that large in the side of your upper is not a great idea.  It leads right to the bolt is just begging for debris. 

Another option would be trying one of the suppressor ready charging handles like the Raptor SD.  

[Chucktshoes]

5 minutes ago, maroonandwhite said:

Circling back around to this. I wonder if leaving the FA out completely would yield a similar effect. I’m sure this piece is going direct the gasses upwards rather than straight out. I’ll try it first without. 

I wouldn’t do that. That valve directs the gas away from the face and body. I suspect an open port that large, besides just being a bad idea on general principles, will cause way more gas to hit the face then before. Even though most may be directed to the shoulder, it’s still gonna hit the face. 

[maroonandwhite]

12 hours ago, mike_f said:

Here's another possibility that might work with your constraints:

The BRT EZTune Gas Tube reduces gas system flow and corrects excessive gas drive from barrels with large gas ports or for use with a dedicated suppressor.

The EZTune Gas Tube replaces the standard CAR length gas tube and requires no modifications or removal of the gas block, making it ideal for barrels with pinned muzzle devices or gas blocks.

After installation, it requires no user adjustments or maintenance.

It is available in several port sizes to meet many small frame AR applications.

This items consists of 1 gas tube and pin.

Installation requires removal and replacement of the gas tube.

Installation is extremely easy and should take less than 10 minutes, start to finish.

https://blackrivertactical.ecwid.com/BRT-EZTUNE-Gas-Tube-Carbine-p103167251

At $55 it's more expensive than the forward assist vent suggested earlier though.  They ask for several parameters regarding how you use your rifle (barrel length, type of ammo, buffer, spring, BCG, suppressor make/model) to determine which gas port size would be appropriate.

I have used gas blocks from BRT, they've been of good quality and have worked well.  I have no experience with these custom gas tubes, however.

That’s an interesting concept but I guess I don’t understand how it would really changes anything.

[Flyboy]

My understanding is a bullet that is sonic, cans wont help much at all. Its the bullet that makes the noise breaking the sound beerier. Not sure the spelling. Sooo cans only suppress the muzzle blast, not the bullet speed.

[Alleycat72]

5 hours ago, Flyboy said:

My understanding is a bullet that is sonic, cans wont help much at all. Its the bullet that makes the noise breaking the sound beerier. Not sure the spelling. Sooo cans only suppress the muzzle blast, not the bullet speed.

All of my guns have a sound level between a 22lr and 22 mag and I have 7 cans by 6 different manufacturers. That's with supersonic bullets. I run them on anything from a 5.56 to a 458.

[mike_f]

On 4/16/2020 at 9:13 AM, maroonandwhite said:

That’s an interesting concept but I guess I don’t understand how it would really changes anything.

My understanding is that they size the gas entry hole in the gas tube (make it much smaller than normal) to restrict the amount of gas transmitted to the BCG. Less violent recoil (compared to a barrel with an oversized gas port), and less gas exhaust from the gas tube/BCG.

I would be interested in their estimate of how long it lasts.  Gas tube metal is pretty thin, don't know how many rounds it would take to see erosion of the smaller entry hole in the gas tube.

[Magiccarpetrides]

On 4/13/2020 at 11:50 AM, my82cam said:

If you don't do something to cut the gas back while suppressed, you will beat your gun up.  I run 10.5 with an AAC M4-2000 can on an M16,  if I don't cut the gas back, it cycles at twice the normal speed.  

Would running a super heavy buffer like an H3 or minimum H2 help to slow that down enough for reduced wear and tear...also better shoot-ability?

[my82cam]

I would just go with an adjustable gas block.   I doubt a heavier buffer would fix all the issues.   

[Johnny Rotten]

8 hours ago, my82cam said:

I would just go with an adjustable gas block.   I doubt a heavier buffer would fix all the issues.   

I would suggest 2 areas to work on.

1. I would address the buffer system first, I'm going to suggest getting the V5 buffer system, its basically 1" longer buffer tube and a rifle buffer that weights a fraction more than a std H3 buffer.

https://www.vltor.com/shop/ar/receiver-extensions/vn-re-a5-a5-receiver-extension/

https://www.vltor.com/shop/ar/buffer-components/sp-a5-a5-spring-and-buffer-kit/

the V5 set up will address several areas from ROF, bolt bounce, short stroking as you change to various lengths (10.5",11.5",12.5",14.5",16") of uppers.

Best $100 bucks I've ever spent.

2. Adjustable gas block

This will fine tune ROF and reduce the amount of gas in your face.

Both will reduce wear on your lower.