AR Sponsor
Posted: 10/11/2005 4:08:54 PM EDT
|
Here's the situation: Got an A2 upper rebarreled with a 16" Superlight and put it back on the original lower. When I started this project, I noticed that my original bolt catch was pretty worn, had some grooves from bolt travel/use. Still held bolt back with empty mag, either manual retracted or during live fire. Replaced the bolt catch, seems to work fine manually with empty magazines--10. 20. 30 rnders from various makers, but doesn't always want to hold the bolt back during live fire. Tried single rounds in mags and it usually held bolt open on empty mag, but not 100%. Removed new bolt catch and made certain that it didn't have any burrs or other defects, reinstalled it and it seemed to function fine. Still having problems during live fire. Seems to be catching the bolt more often than it was, but is probably still less than 60%. Buffer seems to be traveling in buffer tube/extension without a hitch--Bushy 6 position and gave me no problems before, cannot detect any now. So, aside from the obvious, "if it ain't broke, don't fix it" advice, and the try the original bolt catch--which I will do--any ideas/suggestions to fix this problem? Since it seems to be working better, could it just need break in time? Never had this problem with any of my other AR's so I'm not sure what to think. |
|
pics of the bolt? lower? could possibly be the bolt hanging too low? bolt catch binding in the lower and not allowing the catch to fully seat in turn forcing the bolt to drag on it? bad bolt catch? out of specs and too tall? something in the crevices of the bolt catch not allowing it to seat? |
|
The Bolt Catch is from DPMS. Shooting m193. No camera = no pix. The bolt catch seems to function fine manually, and doesn't bind when I move it with my finger. What gets me if the sporadic nature of the malfunction. Hopefully, I can get the old catch in tonight and try it out tomorrow. Thanks for the replies! |
So, I put the original catch back in, and it seems to function well manually. Smoother than the new part. Unfortunately, I am still having the intermitant malfuntion. Everything seems to be fine and dandy, and this lower was 100% with the old set up. I'm wondering if there is a problem with the gas tube/port? Wouldn't that cause a more consistant failure though? The only failure is when the mag runs dry and the bolt doesn't stay locked back everytime. If it were a gas problem, I would think that I would have other problems due to short stroking, but as long as there is ammo, the weapon cycles fine. I have tried many many different mags of various capacity and maker with the same results. I'm stumped. HiveMind help me! |
|
Wouldn't a short stroke due to gas flow be a constant problem? About 85% of the time the bolt catch locks on an empty mag during live fire, and every round chambers and fires. I guess I should put a different upper on this lower and see if I can isolate the problem to the new upper. By the way, I did check the bolt/bolt carrier and key, all seems to be aok. |
Not always... The gas port hole might need opened up a few thousands more... Excessive gas flow could cause erratic behavior that will create the trouble your experiencing too... Measure the gas port hole to see where your at... |
| I was having aproblem with a DPMS lower, it would lock open with some magazines but not others. I did the short stroke test, holding the bolt catch while firing, and it only locked the bolt back when I really pushed it hard. I think there was something keeping the bolt catch from fully moving intot he path of the bolt. Maybe the bolt catch was out of spec. Dunno. I haven't resolved it, I just use the mags I know will work in that rifle. |
AR Sponsor