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ByronF
December 25, 2016, 10:40
Guys

Its my understanding that some have issues of gas in the face from blowback 9mm AR. Not being locked breech, it seems to me the longer the barrel the more gas will be vented into reciever. Is this so?

Im considering an 8" barrel.

W.E.G.
December 25, 2016, 10:44
9mm rifle needs a little fan bladed 45 off the pic rail.

nopec
December 25, 2016, 11:08
Maybe but there are both diy and commercial charging handle mods to address it .

2barearms
December 25, 2016, 11:42
I think you are getting bad info. I've been a big fan of the 9mm AR both as a
Sub and Hypers. Never had gas in the face. If you shoot factory ammo you have no idea what propellant you have, we load all of our specialty ammo with
Winchester AutoComp. Burns clean and won't foul your AR or pistol nearly as bad. If you are shooting suppressed a pistol length is more friendly to faster ammo. For instance I shoot Fiocchi 158's in my 16" and 124's or 147's in my 8.5.

I like the Trident 9 can for both my pistol and carbine shooting pleasure.

yellowhand
December 25, 2016, 12:26
I run mine with Unique powder, no issues or concerns.
The extra finger that grows a little on my left hand after a prolonged shooting session, doc just snips off at his office.:)

GOVT1911
December 26, 2016, 22:16
I've run quite a bit of win and Fed factory ammo and a couple k of my reloads using titegroup through my 9mm AT with standard charging handle and I've never had any gas in the face issue.....

Lee Carpentieri
December 27, 2016, 22:06
How can a AR-9mm be throwing gas in anyones face? The AR-15 9mm is a blowback weapon in design, HENCE NO GAS TUBE for gas to come back at you. I Run a Transferable Factory Colt M16A2 9mm with a short 7 inch DOE barrel with one of the First dedicated Flat top 9mm uppers made, NEVER HAVE I HAD GAS THROWN BACK IN MY FACE AT ALL. SOUNDS like internet BULLSHIT AGAIN.

ByronF
December 28, 2016, 11:20
Calm yourself, LC. Blowback guns run dirty for a reason. The gas tube that dumps some trash into the receiver is called the barrel. The opening of the breech is delayed only by the mass of the BCG+buffer, and force of the spring. I dont see how either of these facts are open to conjecture. It's gas pressure that does the blowing back, after all.

My question is whether there is a noticeable difference between say a 16" vs an 8". To the extremes, a 10' long barrel will, and must, vent considerable gas rearward because the breech is unsealed before the bullet exits the barrel. Conversely, a barrel cut off at the case mouth would puke little gas rearward because the pressure is all released as soon as the bullet advances 1/4".

The nice thing about the AR is that one can play with some parameters: spring rate, spring pre-load, and buffer mass. With something like a Camp 9 you pretty much got what you got. That said, I wonder how many 9mm AR issues are self-induced by running the wrong buffer.

yovinny
December 28, 2016, 12:29
IIRC mine is 11.5" with the long "to-make-16" FH..
Just an old sten mag Oly.
It eats anything...in fact if I'm not shooting reloads, I most times use it to burn up crap surplus and anything dirty or questionable..
And plenty dirty it gets,,,But I've never had gas in the face...:?

YV

Nuttz
December 28, 2016, 12:43
9mm rifle needs a little fan bladed 45 off the pic rail.
Cool idea...

:wink:

ByronF
December 28, 2016, 12:59
http://market.solarrific.com/mobile/Product.aspx?ProductCode=01433#PhotoSwipe148294819 4437

justashooter
December 28, 2016, 15:10
soft commercial primers getting pierced by a less than spherical firing pin will also give you gassy eyes.

Lee Carpentieri
December 29, 2016, 01:55
ByronF, Did you EVEN bother to read what I said, Apparently you zipped through it. There's NO GAS tube in AR-15/M16 Uppers and NONE where made by Colt with gas tube holes in the upper receiver,Hence NO provision for a gas tube was ever cut into the upper receiver PERIOD.Aftermarket YES, Because their nothing more than a 5.56x45 upper sold to the un-educated public that doesn't know any better.

I've been working on Military weapons from around the world since 1969 and currently have the following
S+W M-76
Swedish K
Colt M16A2 R0 635 Factory 9mm
SWD M11 9mm
HK MP-5K-PDW

The MP-5K PDW can fire 9mm+P
The Swedish K can shoot ANYTHING including 9mm+P+ all day long. It's built like a tank and weights like one too compared to the others I currently own.

I've owned over 56 Transferable NFA weapons,Shot them all and repaired them myself when I had too.How many have you OWNED?

ByronF
December 29, 2016, 10:15
Lee

Your first reply came off like a dick. Your second post confirms it.

Byron

justashooter
December 29, 2016, 23:44
I gotta agree with Byron on this one. it is possible that you are also getting some gas back thru the chamber due to early extraction. I had a colt woodsman that would gas this way, prolly due to a weak recoil spring. was kinda a good thing, though, as it didn't have an ejector.

GDavis
December 30, 2016, 15:55
I run 10in Oly on a RR16, never has any gas in my face. Shoots anything I feed it.

Lee Carpentieri
December 31, 2016, 04:05
Takes one to know one and what you posted is typical internet BS as others have posted as not having issues at all, So what's your piss poor excuse?:uhoh:

lysanderxiii
December 31, 2016, 18:33
Guys

Its my understanding that some have issues of gas in the face from blowback 9mm AR. Not being locked breech, it seems to me the longer the barrel the more gas will be vented into reciever. Is this so?

Im considering an 8" barrel.
Actually, barrel length shouldn't make any difference.

When the breech opens up is only dependent on the bolt weight and chamber pressure only, the same loads will have the same chamber pressure no matter the barrel length.

Unless you have such a long barrel that the breech opens before the bullet exits the muzzle.

ByronF
December 31, 2016, 18:58
Takes one to know one and what you posted is typical internet BS as others have posted as not having issues at all, So what's your piss poor excuse?:uhoh:

what a blowhard.