Weird problem with bolt not locking back

[Great-Kazoo]

You are correct.

Jesus is the SON OF GOD. Not the man / woman them self.

[XC700116]

I've got a couple 20's that do the same thing in one of my rifles, none of my 30's or 40's do it, and the 20's seem to work fine in my old rifle. So I'm placing it as a combination of mag and bolt catch on this specific rifle.

[bimmer]

I want the DD to run every mag i put in it. If my BCM has no problem doing it, then the DD has no excuse. Could just changing the FH out make enough difference to cause this?

[Great-Kazoo]

I want the DD to run every mag i put in it. If my BCM has no problem doing it, then the DD has no excuse. Could just changing the FH out make enough difference to cause this?

No. You might want to go back to a standard buffer, Start simple. Guy we were shooting with had a similar issue, with bolt over of rounds. Sent it back to mfg they said, No issues could be found 2X. Took a look at it , BC was filthy AND bone dry. Quick wipe down and application of a very light sheen of oil , it ran flawlessly . Not saying lube is the issue, sometimes an extra pair of eyes might see / notice something you over looked.

[osok-308]

ALWAYS go for the simplest fixes first. Ammo, mags, etc. You seemed to answer your question. it sounds like the 20 round mags. Reminds me that the other day my wife was at work and her car wouldn't start. A couple guys she worked with told me they tried everything and came to the conclusion she had a bad starter, they towed her home. As soon as they left I tried to jump the car. It started right up (yes it was that simple). A lot of guys end up shooting themselves in the foot by assuming the worst and trying to fix the most expensive things first.