Just put together a PSA Classic Colt lower and a Rock River Arms upper.  First day at the range, after three or four rounds, I got a stovepipe every other round afterwards.  Likely cause, if I remember correctly is probably the buffer, correct?  Metalform Colt 32rd mags, tried three with the same results.  I used the buffer and spring PSA shipped with the lower, so I’m not sure what the weight is and I’d like to know what weight would be a safe bet if I need to order a new buffer.

The ejector might need a little tweak.  It should be nearly riding against the bolt in order to catch the rim of the empty.  It seems to be a common issue with PSA lowers, as well as some others.  You may want to try and bend it a bit to the right, toward the bolt.

what ammo are you using?

I’ll take a look!

Herter’s 115 grain.  Shot fine out of my M9.

These problems come up so often I made a copy/paste list in notepad... here you go!

Failure to eject (FTE) / cycling jams / stovepipes / double-feed / triple-feed / weird jams

First: Adjust the ejector and square the ejector tip.

The ejector face needs to ride as high and as far to the right (toward the firing pin) in the bolt groove as possible, just barely touching the bolt as it moves. The tip face of the ejector needs to be flat, smooth, and parallel to the bolt face. No angles, curves, points, rough areas, etc.

WARNING: Some ejectors (Stern, etc.) are hardened steel and will break if bent.

Next: Slow the bolt cycle time down a little so the empties have time to eject:

1) Use a heavy, extended length buffer. A buffer between 6.5 oz. to 8.5 oz. seems to be optimal for most builds. Use an extended-length buffer, or a buffer spacer with a carbine-length buffer, to limit rearward travel. The bolt should stop 1/4" or less rearward from the bolt catch. Buffers that also have sliding weights inside (optional) help reduce bolt bounce, which helps prevent hammer follow and out-of-battery discharges during rapid fire.

2) Are you using an extra power or .308 recoil spring? Try a standard strength recoil spring. An extra power recoil spring may be causing the bolt return to battery too fast, trapping empty cartridges in the ejection port. Most builds do not need an extra power spring to operate properly.

Attached File

Ok, does this look like the ejector is lined up correctly?

Looks like the last 1/4"or so is tweaked the wrong way...also, the end does not look square.
Hold open the bolt and take a picture of the bolt face that shows ejector position and post it. Also, take off the upper and snap a frontal pic of the ejector tip.
Edit: like these..
Attached File
Attached File

Actually, maybe have the ejector tip a bit more in focus than I did

I think you can see well enough on the bolt open picture how ejector position and tip should look...

Definitely!  Didn’t photograph it, but the ejector is definitely off a bit.  I’ll straighten that and I’ve got an extended 8 oz buffer on the way.  Hopefully that’ll do the trick because the rounds I did get through it were pretty sweet!