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Gas blowback on suppressed AR15 - mitigation?


Fullauto_Shooter

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Set up and zeroed my new home defense rifle this weekend; pretty basic little 16" carbine with an AAC M4-2000 suppressor. One thing I noticed was some gas blowback into my face while firing - not unexpected since I dealt with the same thing when firing suppressed M4s in the Army.

Anyone have recommendations for charging handles (or other mods) that will prevent or mitigate the gas blowback caused by the suppressor?

Thanks!

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The RTV trick had being around a while, solid workaround. Gasbuster too. There is also a replacement forward assist knob that has gas port holes in it to direct gas off to the side, but I can't recall who makes it.

But if you don't mind spending a little money, take a look at the MicroMOA gas block. Been using one for a while on my suppressed SBR. No eating gas, as well as better tamed recoil and smooth action for suppressed and unsuppressed operation. I've got a three position plate on mine so the gas can be set for unsuppressed, suppressed, and full gas (the same oversized original gas port size of the barrel). Simple, robust design.

Sent from my SAMSUNG-SM-G870A using Tapatalk

Edited by AustinWolv
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Here is my most recent experience. My Department issued us Gemtech cans for our issued Bushmaster M4s with no other mods. 16" barrels and the stock, non-adjustable gas system. I'm a lefty and this setup was so nasty/unpleasant that the last time we qualified I got an ulcer in my left eye. After that, I took the can off and locked it in the closet. We tested a Gas Buster charging handle (on the same Bushmaster setup) a couple weeks ago by placing trace evidence tape perpendicular to the buffer tube in the same place my face would be and firing 20 rounds. We then put the stock charging handle in and repeated the test. We then placed the tape on white typing paper and there was no noticeable difference in the amount of debris stuck to the pieces of tape.

So, I sold one of my Infinity Limited guns and bought a 10" LWRC and a Surefire Mini suppressor. My stamps finally came in last week and I took her to the range on Friday to sight in the Aimpoint and iron sights. I shot 120 rounds through it and never even got a spec of oil on my glasses. Of course it has a 2 position, adjustable gas block and that may have as much to do with it as the short piston system. I don't really know, but I do love the gun!!

FWIW, my issued Larue .308 is a DI gun with an adjustable gas block as well and it has never bothered me to shoot it.

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I know that it has been covered here before and I think Pat Kelley had a step by step and pictures. Basically you put it in the U clearance cut at the back of the handle, grease up the upper where the handle meets it, to keep it from sticking to the upper. I like to put a foam ear plug up front on one side of the gas tube where the nose of the charging handle goes around it to give it as much space as it can get when closing it. So fill up the U notch and SLOWLY close it until the latch just snaps into the mill cut on the receiver. I also put a little bead at the back of the bottom of the charging handle, but don't put in too much as that is where the gas key ends up on cycling.

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Little bit of mink oil (that stuff for your boots) on the back of the upper......then slobber in the RTV compound in. It will stick to the charge handle and not the upper and will be a perfect fit.

If you put a little of that Mink oil on your fingers......you can wipe that RTV around and make it look real purdy too!!

Tim

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