View Full Version : Bolt catch not working and FTF

09-25-2011, 12:51 PM
Hey guys. Took my first AR build out today and ran into problems.
First, I did not catch the fact the bolt catch does not work. Rookie move.
If there is an empty mag in and you hold hard on the catch it will engage, but will not otherwise.
Second, half the time it will not cycle a second round.
So, I put my upper on a friends lower, my upper cycled no problem.
Put my friends upper on my lower, same problems I am having.
We gauged the bolt catch on mine (Stag lower with Armalite parts kit) and his (pre-ban colt) they were within a couple hundredths of an inch in all regards, at rest, when depressed.
Did not try to post any pictures because visibly we can see no difference.
Any ideas as to the problem would be appreciated!

09-25-2011, 12:55 PM
check to make sure the bolt catch spring is installed and installed properly. also check to make your disconnector spring is not really the bolt catch spring.

09-25-2011, 1:33 PM
Wrong buffer spring?

09-25-2011, 4:31 PM
SDRuger, you win the prize. (I think) The spring measures 12 1/4 inches, which I think is rifle size. Pulling back the charging handle I could not get the bolt to go back as far as my friends, the catch is about a quarter inch from the front of the bolt... The buffer is 3 1/4 inches long which is correct I believe. Will try a new spring.

10-01-2011, 2:30 PM

New spring and still not working. This shows with just the buffer in. What do I have wrong? (In frustration I went down and bought a new tube, buffer, and spring, no love.)

10-01-2011, 3:16 PM
there is a little detent piece on top of the bolt catch spring is it in there or did you just put the spring only in? it will make a dif.


10-01-2011, 3:25 PM
Detent and spring. It is not that the catch won't come up, it is the bolt does not go far enough back to engage it?!? I feel like there is something REALLY simple that I am missing...

10-01-2011, 3:34 PM
Most of the time this is a problem with the stock. I've seen people use an A2 spring when they need the shorter carbine spring, and I have seen problems with people using the wrong screw on the fixed stock.

10-01-2011, 3:54 PM
Yeah, when I measured the first spring it appeared too long. I ordered another, it was 10 1/2", didn't help.
Bought a kit from ATI that has spring, buffer, and tube, put it on, that is what is in the picture...

10-01-2011, 5:03 PM
I am an idiot... On AR15.com someone asked for the depth of the tube, when I went to measure I noticed that I put the original tube back on.
When I disassembled it after getting the second tube I sat them side-by-side to try and see any difference, I could not see any difference.
I then re-installed the original tube thinking it was the second (ATI) one. I just now installed the ATI tube, and everything works perfect!
So, both tubes measured approx. 7.25" long, but the first tube had a depth of about 6.80 while the second (ATI) had a depth of 7"
Bought the first one from a place in Utah... can't find the receipt, was suppose to be American made...

10-01-2011, 5:06 PM
interesting. and theres no spacer inside the originalb thats stuck back there causing the difference in depth?

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10-02-2011, 7:09 AM
Not that I can tell. I assume it was a glitch in the machining? Bummer, can't in good conscience sell it, so I guess I will just toss it.