Thread: AR15 issues

think so

I have a PRI low-profile adjustable gas block on the way, so hopefully that will solve my problem here.


Alternatively, does someone have an H3 buffer lying around?

G'Day Fella's,
gimp, I'm a bit late to this thread but with a shorter barreled AR, I have seen what they call a "Pig Tail" gas tube.
These gas tubes come back from the gas block then wrap around the outside of the barrel a couple of times, prior to going into the upper receiver.
What they are doing is extending the length of the gas tube on short barreled rifles, there by slowing down the cyclic speed of the bolt carrier.

I just went and Googled AR15M16PigTailGasTube and up it came with a picture and details of the part from Brownells in the US.

Now fella's, I'd like to say I was some kind of authority on Black Guns, but because of some slimy political animal (FJWH), this is not the case!!!

Hope that helps

Doh!
Homer

A pigs tail will change dwell timing more than cyclic rate - although they are both related. Gimps probs are the result of a gunsmith that over drills gas ports all the time

G'Day Spanners,

Is it possible to drill and tap the current gas port and then install an Hex grub screw with a smaller gas port diameter?
Or maybe, install a hollow "Spring Pin" in the current port hole?

Doh!
Homer

It's easier to solder the barrel end of the gas tube and drill that hole the right size or to suit

Spanners, it sounds like you blokes have a good handle on the situation!

Merry Christmas
JB/Homer

Update: I am now about 90% sure that it is UNDERgassing, as it functions 100% with suppressor, 75% with compensator, 0% with no muzzle device.


This means I have bought a useless adjustable gas block, however it also means that it's a way easier fix.


Ejection is actually to ~4 o'clock as observed at the range today.

4 o'clock is about perfect

Does it lock open on last round?

You havnt got something stupid like a carbine buffer or spring in it do you??

Have you measured the shoulder to gas port centre on the barre; and the gasblock back to hole centre?

Remember that a 'normal' AR with handguard front cap spaces the gasblcok the thickness of the cap fwd. If you use this same block without the front cap, then you are a mm or 2 too far back and the holes may not line up properly


Whats your loads?

With suppressor on it functions 100% perfectly, picking up rounds, locking back etc. Without any muzzle device, it doesn't pick up next round or lock back on empty mag.

Rifle stock, rifle buffer and spring.


3 types of factory ammo - Norma, Hornady (55gr) and Belmont (60gr).


The hole in the gasblock is centred over the gas port.

Gas port is ~1.4mm diameter.

BINGO - bigger pls 1.7
My M4 barrels (same as what US Army using) 14.5" are 2mm and a touch overgassed with my hot ammo, then again they might want to throw brass fwd to get it out of guys way beside you

Originally Posted by Spanners

BINGO - bigger pls 1.7

Thats about 1/16" if you have imperial drills