AR15 7.62x39 feeding fix

[cbrudedog]

I just got a new Radical Firearms 10.5 pistol upper in 7.62x39. It would shoot one shot at a time. No feed and No extraction. The bolt was not coming back far enough to load the next round. Gas pressure problem. I checked the gas block alignment and the gas key and they were fine. I drilled the gas port on the barrel out to 7/64 and fixed that problem but then it was picking up the new round without ejecting the spent shell. Extractor spring was crap so I stuck in a new spring and a rubber o-ring and fixed that. I also opened up the M4 feed ramps a bit while I had it apart just for the hell of it. It is running fine now.
I just wanted to let everyone know my fixes just in case someone else was having the same problems.

 

[JeeBus91]

Th first problem could've been the buffer/spring, what bcg are you running?

 

[fattboyzz]

bushmaster feed ramps 762×39

 

[hikingthehills]

I just got a new Radical Firearms 10.5 pistol upper in 7.62x39. It would shoot one shot at a time. No feed and No extraction. The bolt was not coming back far enough to load the next round. Gas pressure problem. I checked the gas block alignment and the gas key and they were fine. I drilled the gas port on the barrel out to 7/64 and fixed that problem but then it was picking up the new round without ejecting the spent shell. Extractor spring was crap so I stuck in a new spring and a rubber o-ring and fixed that. I also opened up the M4 feed ramps a bit while I had it apart just for the hell of it. It is running fine now.
I just wanted to let everyone know my fixes just in case someone else was having the same problems.

Thanks for the heads up, I just got a 7.62 PSA upper and havent even had a chance to shoot it. If I have problems I will be doing what you have done.What kind of mags are you using and could you post pictures of the feed ramps after you did them.

 

[cbrudedog]

I'm switched out bcg and the buffer and spring with my 7.62x39 rifle just to check all that. The extractor was much tighter in my Sota bcg and the extractor itself beefier in the Sota bcg. Ive ordered a heavy duty 7.62x39 extractor for the Radical Firearms bcg. I doubt I will order from Radical again. My Sota and PSA uppers are much better quality.

 

[cbrudedog]

ASC mags. I just rounded off the sharp edges.

 

[cbrudedog]

I used a chainsaw file in a drill and screwdriver with sandpaper wrapped around it. Hahaha

 

[fattboyzz]

I used a chainsaw file in a drill and screwdriver with sandpaper wrapped around it. Hahaha

Looks jam up

 

[hikingthehills]

Awesome, thanks man!