Ohioans For Concealed Carry Discussion Forums

I am having a problem with my Kaw Valley Precision 9mm BCG that I am hoping you can help me with. I have a 9mm AR that I installed a KVP blowback BCG in. However, if I have a magazine inserted the BCG seems to seize up. It takes great force to pull back the bolt with the charging handle, and if I can get it back, when I press the bolt release, the BCG only travels forward about 1/2 - 3/4 the travel length before it stops. If I get a round in the chamber, the rifle fires fine but the bolt doesn't travel back far enough to even eject the brass casing much less all the way back or forward feeding the next round. If I remove the magazine while the bolt is stuck in the "half-way" position the bolt will slam forward. The bolt cycles fine without a magazine inserted. My trigger is a Spikes Tactical Battle Trigger, the magazines I've tried are 20 rnd and 32 rnd C-Products Colt style magazines. The lower is a QC10 Colt pattern lower.

Once you have a round chambered, will the bolt cycle if you remove the magazine before firing?

If it does, either the ejector is 'out of whack' or the magazine is riding high.

With the upper off, insert a loaded mag and see if the ejector contacts the rounds. If it does, the ejector needs adjusted, modified or replaced.

Next, I would look at trying a different brand of magazine, since both of yours are from the same manufacturer.

If a different brand gives no joy, you may need to file down the top of the magazine catch a little.

Cut one turn off the bottom of the magazine spring.