AR pistol cycling question

[VictimX]

Well I have a 7.5" AR pistol with rifle length pig-tail gas tube cambered in 5.56 nato. The gun fires well and cycles but often will not eject the spent round and chambers the next round into the already chambered spent round. I'm thinking I either need a stronger buffer spring or heavier buffer but want some opinions before I start spending money and buying all kinds of parts.

[SkyHawk]

I would post this in the centerfire rifle forum, a lot more AR guys hang out there. I would be looking at extractor and ejector first, try another assembled bolt if you have one to rule it in or out.

[VictimX]

I was thinking that but I've seen AR pistols here so I was unsure, any ideas on how to move this thread?

[TygerAR]

Sounds like you are over gassed. Common in pistols. Yes, go with a 4 or 5 oz. buffer.

[Glockrocks]

Sounds like you're under gassed, bolt not moving far back enough to eject the spent casing and strip a new round into battery. Try a straight gas tube instead of the pig tail and see how that works.

[Dragginpanda]

Get an ejector spring upgrade, costs a few bucks and that's it.

[VictimX]

Sounds like you're under gassed, bolt not moving far back enough to eject the spent casing and strip a new round into battery. Try a straight gas tube instead of the pig tail and see how that works.

It's not ejecting the round and loading a round behind it. I might as well get a heavy buffer and heavy ejector spring kit.

[Chunky_lover]

what ammo was used


well things to check is if gas block is lined up
hopefully the gas hole in the barrel was correct size


does it lock back on an empty mag, when shot

and your using stock carbine buffer spring and buffer?
because your using rifle length pigtail whats the reason behind doing that
does it make the gasses take longer to work the bolt carrier back

im no barrel expert but I would think 7.5 inch barrel gas hole is carbine length and can use carbine length gas tube
at least mine does


the only problem I had on mine, ended up being 1/4 inch shorter buffer tube then 2 others I measured
but my problem was not locking back on empty mag
everything else was fine

I always recommend just taking a minute and measure the inside depth of the buffer tube
could be something stupid like that
one sign was my buffer had marks it was hitting the tube inside then after I measured it made sense

before I found out my buffer tube was shorter they were saying use heavier buffer but those are around $30
I dont think I needed the one I bought but since it works with it in I kept it installed



ive also read alot in the past most dont ever use the pig tail tube
not sure the reason why just stuck in my head no one uses that







gets expensive now guessing on what parts to buy to solve this problem
and getting range time to keep going back to test

good luck

[mhus883]

A barrel under 10.5inches on a gas system has problems due to the gas system being so short the when the gas reaches through the port and all the way back to push the bolt back the spent cartridge is still under a lot of pressure and causes ejection issues gas port hole on the barrel should be at least 9 inches to function reliable. Hope It helps .

[walmart_ar15]

Do a search in the rifle forum, this exact problem has been discussed multiple times.

Summary, under gassed, switch pigtail to straight gas tube, shoot on.

[VictimX]

Gas tubes for rifles, carbines and pistols are different and yeah they are trail and error I found on my other pistol... here is my issue on this one.



I have a 7.62x39 chambered on the same platform (7.5" barrel) using a pistol length gas tube, heavy weight buffer/spring with enhanced firing pin and extractor spring, runs perfect. Most parts that were changed out from that build were put into this 5.56 build.

[VictimX]

Do a search in the rifle forum, this exact problem has been discussed multiple times.

Summary, under gassed, switch pigtail to straight gas tube, shoot on.

It locks open when empty and chambers another round so how can it be be under gassed?

[Chunky_lover]

Gas tubes for rifles, carbines and pistols are different and yeah they are trail and error I found on my other pistol... here is my issue on this one.



I have a 7.62x39 chambered on the same platform (7.5" barrel) using a pistol length gas tube, heavy weight buffer/spring with enhanced firing pin and extractor spring, runs perfect. Most parts that were changed out from that build were put into this 5.56 build.

you modify the mags
ive seen a video on what to file down to make them feed smoothly
compare that mag to an ak and you can see what to do

[VictimX]

I have used many types of mags but forgot to mention the gun runs almost perfect with the same ammo being stored in the shade but when the ammo is kept in the sun it has these issues. I'll go with a little heavier buffer and enhanced extractor. Once I get the parts I'll post an update.

[walmart_ar15]

It locks open when empty and chambers another round so how can it be be under gassed?

So it cycles fine, what's the prob? Also how do u fit a rifle length pigtail gas tube to a 7.5" barrel?

Again do a search, lots ideas out there. if u believe u r extracting before the chamber pressure dropped causing FTE, then try stronger extractor spring, o-ring etc. they r cheap bandaid solution.

With pig tail gas tube, unless u bored out u r gas port, it's low prob having it be over gassed with 7.5" barrel. But I have seem stranger things.