View Full Version : Issue with Bolt Locking after last round on AR

05-17-2012, 2:34 PM
Calgunners - What's the main reason my bolt doesn't lock back after the last round. AR is a few years old.

05-17-2012, 2:47 PM
Has it been working for a few years and just recently stopped locking back? Perhaps your gas block has become loose and that has dropped the pressure. Also, the obvious, are you using new mags?

05-17-2012, 3:11 PM
Djleisure- No problems in the past. It's been happening lately. My thoughts were the Mags also. It's mostly the mags that are either 10/20 or 10/30. I have 1 steel 10 rounder that still works like a charm.

05-17-2012, 3:18 PM
Sounds like a mag problem to me.

05-17-2012, 3:22 PM
New springs for your mags.

05-17-2012, 3:34 PM
Troubleshooting an AR, start simple then progress.
BCG (gas key loose, gas rings worn or missing, extractor)

If your rifle were mine, I would drop the lower, insert an empty mag, and inspect the interaction between the follower and the bolt stop. If it engages the bolt stop reliably under static testing, but fails to lock back when shooting, I would try and borrow a friends known good mag and try again. It's possible yours needs a new spring. Mags are consumables to me. If I start having issues with one, I pitch it and replace it. (pre ban hicaps excluded)
After mags I'd keep working down the list. Good luck!