Ar10 bolt catch question.

[Rob]

New into AR 10 builds so I have a rookie question.   I have done several ar15 builds though.

I have a dpms compatible lower that I built.  I used a dpms lower kit and a geissele trigger.  I bought a complete upper that was said to be dpms compatible as well.  Everything mates up and the bolt will cycle when pulled by hand  (have not fired it yet).

The issue I am having is that the bolt catch does not hold the bolt open on an empty mag, or when I manually push the bolt catch up.  It appears to be too short to reach the bolt.

Any ideas?  Is there a specific bolt catch I can replace the ones I have with that will reach the bolt?  The mag does push it up, it just won't physically go high enough to retain the bolt.

This is an AR stoner upper chambered in 308 win.

[hunter399]

Had a ar15 do the same thing ,brought it home and checked the hole that the spring and bolt catch plunger goes into and there was dirt and junk in there it was a Anderson lower.
Also where the plunger hits the bolt catch I have removed a tiny bit of material from a bolt catch before to make it so the bolt catch will work.
But always check that the spring and plunger are working good first.

The gun that had dirt in it,I punched the roll pin out just far enough to get the bolt catch off took out spring and plunger ,cleaned out hole with tiny screw driver and air compressor,put back together and bolt catch has worked fine ever since.

[jay.sharkbait]

A2 buttstock?

If so the screw may be too long. Or you are using the wrong buffer.

[hunter399]

I would look inside there as you work the bolt catch and make sure it's not hitting the upper on the right side .
This guy had a problem of bolt catch hitting his upper,but I would never take material off of the upper as he did ,i would remove material from bolt catch till it does not hit upper.

[Rob]

I have 2 built out lowers, one with a or a stock and the other with a troy industries stock.  Both have the same symptoms and use totally different buffer systems.

I will pull the bolt stop and make sure it is clean in there with nothing impeding the movement.  It does seem to have a full range of motion though.  Interesting video.  I am with you-i would shave material from the catch, not the upper!

 I will have to try a friend's upper and see if his does the same thing with a different bolt carrier group.

[Rob]

I pulled the bolt carrier group so I could see better and it does seem to be catching on the side of the upper like the video. 

Looks like that is my problem!  Thanks!

[hunter399]

I pulled the bolt carrier group so I could see better and it does seem to be catching on the side of the upper like the video. 

Looks like that is my problem!  Thanks!

Glad to help!
I would take bolt catch off and grind off the corner of catch or a little material and see if you can get past that upper tiny bits at a time till it clears,don't grind your upper like in the vid ,if you mess up a bolt catch very little money to replace,if you mess up your upper a lot more money to replace ,hope it helps,goodluck ,post it up if you get it fixed.

[Rob]

exactly!  I have zero interest in grinding away the upper!!

[Rob]

Fixed!  I had to shave quite a bit off the side of the bolt catch but it now holds.  The upper was pushing the catch down when it closed. 

Thanks again!

[hunter399]

Glad to hear ,there's always more than one way to skin a cat.

[724wd]

had the exact same problem on a buddy's AR-10. Took me a while to figure it out, but same solution.