Confirm Action

Are you sure you wish to do this?

Confirm Cancel
Member Login
Site Notices
10/20/2017 1:01:18 AM
9/22/2017 12:11:25 AM
Posted: 7/20/2005 9:03:04 PM EDT
Build design - Carbine upper from Bushmaster with TiN bolt and carrier group from Del-Ton. The lower parts kit is from Bushmaster. I assembled the parts on a GSE lower. Vltor Cub Carb buttstock.

Problem - when I insert empty mag and try to pull back the bolt, it only goes a short distance and will go no further.

Observations - the bolt release latch is able to raise up farther than my other receivers do and also has more horizontal "toggle" play than others as well. Also, it catches the very back of the mag and can get jammed when the upper is not on. I think this is what is happening when the whole thing is assembled.

Possible failure modes: Release gap machined into lower is too wide? Bolt release is too skinny? Recess for bolt release plunger and spring is too big? Just a bad Mag follower? Bad Bold?

Can someone help me trouble shoot this? I need advice on what to do next based on your experience.
Link Posted: 7/20/2005 9:28:56 PM EDT
Link Posted: 7/20/2005 9:35:37 PM EDT

Link Posted: 7/21/2005 7:19:47 AM EDT
Did you by any chance stick some c-cell batteries into the buffer tube?

There is a point on my Colt that if I charge the weapon and I only pull about 1/2 way, the bolt will get stuck 1/2 way over the magazine. I can clear this just by continuing to pull back on it. There just seems to be a point that it catches on 1/2 way through cycling if I release the charging handle too soon. You might want to see if yours is doing this (sounds like its doing it in a bad way) and see what it could possible be hung up on.
Link Posted: 7/21/2005 2:38:33 PM EDT
I tried to pull it back smooth and firm, it just gets stuck. I really pulled hard on the tac latch and it won't budge. I clearly think the problem is the bolt catch lever or the receiver. I just don't know which. I will eventually check to see if the receiver is OOS. If not, I will replace the spring, plunger, and roll pin. If that doesn't do it, then the lever. If that doesn't do it, then who knows.
Link Posted: 7/21/2005 2:52:48 PM EDT
Good luck man I'm sorry you didn't get any ideas about what this could be, most of the time you'd have an answer to your problems within 10 minutes on this board!!
Link Posted: 7/22/2005 10:29:43 AM EDT
seems like people's interests wax and wane like the moon. Next time I will have to include BOTD or something to get a response.
Link Posted: 7/22/2005 3:14:45 PM EDT
Do you have the problem when the gun is empty?

Did you try w/ different mags?

If you have different lowers try changing the bolt catch and see what happens.

Please keep us posted.

Link Posted: 7/22/2005 4:52:18 PM EDT

Originally Posted By JoseyWales:
seems like people's interests wax and wane like the moon. Next time I will have to include BOTD or something to get a response.

Yeah, the magazine gig is a good idea. If you have more than 1 I would definitely try it out. When I do the 1/2 pull and it locks, its over the magazine. It sounds like you have an extreme version of what happens when I do this. If you don't have more than one take it to your local gun joint and see if they have a mag you can try out...

Link Posted: 8/11/2005 4:16:24 PM EDT
I just ordered some mag kits from Magpul. I will update my mags and then try cycling it with an empty mag again. I noticed that the catch can tilt higher than my other lowers. I think they machined the roll pin holes and the plunger hole too big. I will try the new mags, if that doesn't work....then I will have to really grab my ankles!
Top Top