AR cycling issue

[briansmithwins]

Gas tube has already been replaced in post #7.

BSW

 

[oldschool45]

A through cleaning of the barrel & chamber appears o have fixed the cycling some but its still inconstant few miss feeds and not locking open on an empty mag. Thinking this may be a too stiff recoil spring or possibly the bolt catch assembly the pins look like its been "worked on"

 

[goon]

Did you ever say what ammo you're using? Some guns won't run worth a damn with Russian steel case ammo. It's not loaded the same as XM-193 or M855 spec ammo, and the different pressure curve from the powder the Russians use isn't well balanced with the AR gas system. Plus the cases don't expand the same as brass, so you get a little more soot making its way into the chamber. It just causes problems with some guns.

You also could have the wrong weight buffer in a gun built or worked on by someone who didn't read enough before buying parts. A couple of the factory built AR's I've had were marginal with steel case Russian ammo and even noticeably less enthusiastic with civilian .223 ammo due to gas port / buffer weight combination.

 

[oldschool45]

This last time I isolated the ammo and only used Aquila 5.56Nato 62grain. I asked for the hottest 5.56 available. I think I had copper fouling in the barrel causing intermittent crap with the gas port. I think the remainder of the issue is in the lower buffer weight or spring or the bolt catch which may have a marginal spring or be pinned wrong.