AR 308: Bolt catch doesn't catch consistently

[44Blam]

I have an AR 308 and the bolt catch catches occasionally, but not consistently.
The bolt didn't catch at all in the beginning. In fact, I could pull the bolt back and lock it with a magazine in and drop the mag and the bolt would go forward.
After about 30 rounds, it seems to catch occasionally.
Anyone know of places with maybe an oversize bolt catch? Or is there a better way to troubleshoot?

[wildwilly]

I had a similar issue with my AR-15. I thought it was the bolt catch. But it only happened with my older magazines. I replaced the springs in all my older magazines with Wolfe springs...solved the problem.

[eck0313]

As WildWilly said, check your magazine springs. It’s a good idea to mark, or number your magazines so you can tell if a particular problem only occurs when using a specific magazine.

I was running a carrier weight in my AR when I was competing, and the extra mass (and inertia that goes with it) would sometimes accelerates the wear/ causes the problem too. If the bolt catch appears to have any wear where the bolt impacts it, I would think about replacing as well. A soft roll pin can get bent also; make sure the bolt catch can be rotated as designed with no dragging. Finally, the holes for the roll pin through the bolt catch can be all over the place dimensionally. An oversized hole will allow the catch to rotate, and allow the bolt to ride off more easily, or prematurely.

[popper]

Yes, check the mags. If carrier doesn't move freely, won't stay LB. Shape of AR10 and AR15 bolt catch is different. Finish of the lower can cause problems but it will wear to solve that problem. Lose upper/lower can also be a problem, but it usually is the mags.

[Bubba w/a 45/70]

If you want this figured out completely, go over to https://forum.308ar.com/ with your 308ar rifle specs and they will help you out very quickly.

Be ready to post pics, be able to tell what brand of rifle, parts, ect., and you will have an answer.

[Bubba w/a 45/70]

As an aside, I am not denigrating any help or advise from here, but those guys know what makes those 308ar's tick......and the rifles are a different breed than ar15's are. Too many parts tolerance stacking problems, manufacturer problems, and sometimes just plain ignorance of the person putting one together when they are perfectly fine putting together ar15's without problems. 308AR's are just that finicky when not completely assembled correctly, whether factory or ont.

[44Blam]

As an aside, I am not denigrating any help or advise from here, but those guys know what makes those 308ar's tick......and the rifles are a different breed than ar15's are. Too many parts tolerance stacking problems, manufacturer problems, and sometimes just plain ignorance of the person putting one together when they are perfectly fine putting together ar15's without problems. 308AR's are just that finicky when not completely assembled correctly, whether factory or ont.

This is what I think ^^^... Thank you, I'll go post up there when I get a chance.

[RichardB]

call these folks... http://www.sprinco.com/tactical.html

SOunds to me like a set of incompatible buffer tube length, buffer, spring and spacer. It may be mushrooming the spacer at the rear. It works occasionally now when it did not before.

[popper]

You can use the charging handle to get LB. Buffer stuff is OK. I assume the latch is free to move and does spring back when no mag and lower is separated. The 'toe' of the catch has to slide over the top of the mag carrier when NO rounds are in the mag. Sometimes the carrier is too high. The back of the latch hits the bottom of the BGC and holds bolt open. Just cycle slowly by hand looking into the ejection port. You will find the problem. Not rocket science.

[cmdrted]

all good advice. Definitely make sure the catch freely goes up and snaps down freely by hand. this can be bent just by letting the bolt carrier slam into it. also make sure you installed the spring. this has happened once or twice in my builds. check to make sure the catch is for a 308. they say there is little difference but I beg to "differ"