Mitigating/eliminating blowback w/5.56mm can

[mbogo]

I took my new YHM Turbo out today and used it on American Eagle 55gr. FMJ ammunition and two AR-15 hosts: a 10.5" SBR and a 16" carbine.

I noticed debris hitting my face when I fired (with both guns); no debris was blown back when I fired unsuppressed.

When I got home, I performed Jeff's Gas Buster Modification so I should be okay next time out.

What does the backpressure caused by the can do that results in the debris?

What can I do to eliminate this without the Gas Buster mod?

Would using a heavier buffer help?

[doubloon]

get a superlative block, vent it out the front

or

get a vented bolt carrier

never heard of Jeff

[ECCO Machine]

What does the backpressure caused by the can do that results in the debris?

The question is the answer.

What can I do to eliminate this without the Gas Buster mod?

Would using a heavier buffer help?

Might. Adjustable gas block would help more. You want to reduce the opening speed, not so much worry about slowing the carrier down at the rear of it's travel.

[mbogo]

Thanks for your replies. I will check into those options.

For those interested in the Gas Buster Mod, see https://www.ar-15.co/threads/10446-Jeff ... dification

mbogo

[doubloon]

Now that I've heard of it mark me down as not interested.

This is right up there with the rail mounted battle axe for me.

[T-Rex]

Get the gas block. Not a huge investment for what you get in return.

[mbogo]

Get the gas block. Not a huge investment for what you get in return.

It will get expensive if I get one for all seven 5.56 uppers

mbogo

[doubloon]

If you want a cheap hobby you can always take up paintball or baking.

[fishman]

Get the gas block. Not a huge investment for what you get in return.

It will get expensive if I get one for all seven 5.56 uppers

mbogo

Then get the gemtech bolt carrier (or 2) and swap it around between rifles.

[bani]

AR gas vent is one of the most effective mods I have found to reduce blowback.

[T-Rex]

AR gas vent is one of the most effective mods I have found to reduce blowback.

The gas vent doesn't reduce blowback. It simply vents it away from the shooter's face. You're still allowing unnecessary pressure and gas into the receiver and against the recoil system. The proper way to go about it is by controlling/eliminating the amount sent down the gas tube. A gas block is the appropriate device to use. Keep it in the barrel and out the suppressor. Or, with the Superlative, you vent excess forward and don't use it to operate the bolt.

[thequietertimhall]

[quote="mbogo"

What does the backpressure caused by the can do that results in the debris?

What can I do to eliminate this without the Gas Buster mod?

[/quote]

The issue here is that suppressors typically get over-pressurized when shooting .
This is a result of trapping the gas internally to cool it. As you continue to shoot, the gas is entering the can at a higher rate than it is escaping out the front. Once the can is over pressurized back-pressure will occur. This is the gas taking the path of least resistance and going back down the barrel and exiting through the ejection port. That is referred to as blow-back and it sucks.

You can properly tune your gun with adjustable gas blocks, vented BCGs and buffer weights but will need to tweak between shooting suppressed and un-suppressed.

There are a few suppressors that drastically reduce back-pressure through unique designs and they eliminate the need to re-tune when shooting suppressed and when not shooting suppressed. The company I rep for is one of these.

[doubloon]

...
You can properly tune your gun with adjustable gas blocks, vented BCGs and buffer weights but will need to tweak between shooting suppressed and un-suppressed.

There are a few suppressors that drastically reduce back-pressure through unique designs and they eliminate the need to re-tune when shooting suppressed and when not shooting suppressed. The company I rep for is one of these.

For optimum performance (in some cases for mere functionality) this first part is true.

No first hand experience with nexgen2 but they certainly sport some interesting technology in their products.

[mbogo]

I've ordered a Superlative Arms .750" bleed-off gas block, and will check its effectiveness once installed.

I don't expect to fire a lot of subsonic 5.56mm ammunition as most won't cycle a direct impingement AR, but if I can get it to cycle with the Superlative, I just might try the Beck Ammunition 77gr. Rex load.

Thanks to all. Even Doubloon (despite his snarky comments ).

mbogo

[doubloon]

...
I don't expect to fire a lot of subsonic ...

It's not just a subsonic issue.

If you tune the block for optimum performance with a particular ammo either suppressed or unsuppressed then when you change ammo or add or remove the can.

You can always choose to run it slightly over-gassed which will mitigate cycling issues when changing ammo or switching between suppressed/unsuppressed but if you do you run the risk of gas in the face anyway.

[mbogo]

Understood. I was merely pointing out that I would be using mostly supersonic ammunition. The different modes would just make it easier to switch back and forth between subs and supers without a lot of trial and error .

mbogo

[thequietertimhall]

No first hand experience with nexgen2 but they certainly sport some interesting technology in their products.

This we can correct. I am headed out to Houston next week for the TTPOA conference. We also have a DFW based rep that is down in your area often. Shoot me an email and we can set up a demo for you. [email protected]

I was a skeptic when I first saw this design and now I rep for the company.

[doubloon]

I saw that, I'm intrigued. I'd not heard of TTPOA until you mentioned it.

I'm also following the thread where you plan to attend a metering day in GA If that works out well for you there is another event being talked about for October in Houston-ish that may be bigger.

[thequietertimhall]

I saw that, I'm intrigued. I'd not heard of TTPOA until you mentioned it.

I'm also following the thread where you plan to attend a metering day in GA If that works out well for you there is another event being talked about for October in Houston-ish that may be bigger.

I'll have to look into that one and get our TX rep, Paul Bonelli, down there for that one.

[Historian]

If you want a cheap hobby you can always take up paintball or baking.

Having finally recovered from laughing at your clever dictum I can
type a thank you for cheering up a dismal day!

Oops, is that UPS ringing the bell with a delivery of those outrageously
priced digital micrometer, caliper, and tools=> ∞......? : )

Best,
my friend.

[doubloon]

... outrageously
priced digital micrometer, caliper, and tools=> ∞......? : )

Best,
my friend.

TOYS!

jealous

[mbogo]

The Superlative Arms adjustable gas block with bleed-off worked. I've ordered more of them.

Thank you

[gsyoung54]

I took my new YHM Turbo out today and used it on American Eagle 55gr. FMJ ammunition and two AR-15 hosts: a 10.5" SBR and a 16" carbine.

I noticed debris hitting my face when I fired (with both guns); no debris was blown back when I fired unsuppressed.

When I got home, I performed Jeff's Gas Buster Modification so I should be okay next time out.

What does the backpressure caused by the can do that results in the debris?

What can I do to eliminate this without the Gas Buster mod?

Would using a heavier buffer help?

I don't get any blowback with my 5.56's and various cans and I don't think you should be either with the turbo mount and suppressor design I don't see how. Are you shooting lefty and getting stuff in your face from the ejection port? Are you shooting too close to a dirt hill? Like 15 yards away? I get a lot of blowback filth in my uppers, especially bad with commercial Blackout... but never have anything hit my face from a sealed can screwed tight onto a mount which is Rockset or Vibra-Tited to the 1/2 x 28 threads...

George

[mbogo]

George,

Yes, I shoot lefty. It's the first can/cartridge combination I've had the issue with. The 300 BO, .308 Win., and .458 SOCOM did not produce any noticeable blow-back.

Particle blow-back was very slight with the 16" upper, and I might not have noticed it all had I not been pelted while shooting the SBR first.

mbogo

[gsyoung54]

George,

Yes, I shoot lefty. It's the first can/cartridge combination I've had the issue with. The 300 BO, .308 Win., and .458 SOCOM did not produce any noticeable blow-back.

Particle blow-back was very slight with the 16" upper, and I might not have noticed it all had I not been pelted while shooting the SBR first.

mbogo

I notice a lot of crud escaping my ejection port and my upper receiver always gets filthy with suppressors but the ejection port is well ahead of my face.

There are some nice lefty AR uppers and guns out there from several companies... maybe that would help?

George