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 Bolt catch problem - unsure of next steps...
David_Shea  [Member]
1/2/2012 7:24:01 PM
I have an home-built rifle modeled to be an M16A1 replica.

Here is what is involved:
Surplus M16A1 upper with a semi-auto bolt and bolt carrier
Rock River A2 lower with A2 lower parts
A1 grip and A1 buttstock (no trapdoor)

Here is the problem - Regardless of magazine used (20 rd with aluminum follower, 30 round with black or green follower) the bolt catch will not hold the bolt back. The only way I can get it to function is if I manually force the catch to its maxiumum height and then slowly put the bolt against it. If I knock the rifle a certain way, or bump it against the ground, etc., the bolt will slam forward.

The bolt catch DOES move freely. It does lift up when a mag is inserted. It doesn't appear "hung" or binding or anything. The spring moves freely, etc.

Thinking I could be missing something, I replaced the bolt catch, spring and detent - same result.

When I switch uppers, and put a different upper on the rifle, i get the same problem. If I put this upper on a different lower, the catch works fine.

Could it be that the buffer spring is too strong, and is trying to push the bolt forward with such force that the catch is giving way?

I am at a loss as to what to try next...

Any tips would be appreciated. I am thinking my next step is to put a different stock set and buffer, etc on that lower and test again....

David.
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HK_DUDE  [Team Member]
1/2/2012 7:29:13 PM
Do you have a crazy heavy spring in the bolt catch?

Is the bolt catch completely out of spec?

When you say you replaced it.....do you mean you took all the parts out and replaced the same parts back in the lower? or did you use different parts?
j3_  [Team Member]
1/2/2012 7:48:30 PM
Make sure you have the correct shorter screw in the A1 stock.
RotaryJihad  [Member]
1/2/2012 8:14:50 PM
Originally Posted By j3_:
Make sure you have the correct shorter screw in the A1 stock.


Stupid question, how would this affect the bolt catch?
j3_  [Team Member]
1/2/2012 8:19:19 PM
It causes it to catch the front of the carrier instead of in front of the bolt.

When I post comments I am not trying to guess what the answer is to the problem. Only adding other ideas to try from posts I have seen over the years that caused others problems.
David_Shea  [Member]
1/2/2012 8:46:59 PM
Originally Posted By j3_:
Make sure you have the correct shorter screw in the A1 stock.


I am not sure - do you know how long the screw should be?

To the other question - I did actually replace the bolt catch, spring and detent from another lower kit I had. Did not help at all.

-David
David_Shea  [Member]
1/2/2012 9:21:14 PM
Originally Posted By j3_:
It causes it to catch the front of the carrier instead of in front of the bolt.

When I post comments I am not trying to guess what the answer is to the problem. Only adding other ideas to try from posts I have seen over the years that caused others problems.


I just checked the rifle, and what you described is EXACTLY what is happening....

The degree to which the bolt catch is engaging - it is catching on the BOLT CARRIER, not the bolt face- as is the case with the other rifles I checked.

So the solution is apparently this screw idea? Could you walk me through the issue a bit more?

-David
David_Shea  [Member]
1/2/2012 10:08:52 PM
Just checked and it was the A2 screw - cut it down with my Dremel, and now everything functions fine...

Basically, had an A2 screw in an A1 buttstock - screw was hitting the back of the buffer preventing it from traveling all the way to the rear.

-David
HK_DUDE  [Team Member]
1/2/2012 10:16:40 PM
Originally Posted By j3_:
Make sure you have the correct shorter screw in the A1 stock.


Great Work Sir!
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