AR Sponsor
Posted: 7/25/2005 8:39:24 AM EDT
|
This weekend, I sometimes experienced a failure-to-feed/jamming problem with my AR. It's a Colt Sporter-Target lower and a Colt upper converted to an "M4'gery" set-up. What happened is the following: About once, twice or three times of 30 rounds loaded/fired out of a couple of my USGI (Center manufactured, black follower) mags, the bolt doesn't seem to "pick up" the round and feed it correctly into the chamber. Rather, what apparently happens is that bolt lug seems to start "pushing" the round forward and then, after about a half inch or so of movement, the bolt seems to "ride over" the top of the cartridge, with the cartridge being more or less "caught " (at the rear of the cartridge) between the magazine and the bolt. This doesn't seem to happen with any of my USGI 20's. I haven't tried any other of my 30's----didn't have them with me this weekend. Ammo used was Wolf polymer. My thought is that what I have is most likely a magazine problem----true----or not? The thing is, the bolt will lock to the rear after the last cartridge is fired---which tends to make me think that the mag spring, otherwise, may be okay. Any recommendations or thougths from the group, Tweak, etc.? |
|
Was the FTF happening in multiple 30 round magazines? If not, it sounds like the ammo is nose-driving. Try a green follower and possible a new spring. I had the same thing happening in some old Colt 20 round mags. I replaced the spring and solved the problem. In your case, I would also change the follower to a green one. I hope this helps. |
True Try other 30 round USGI mags. If they work, you can probably salvage the other mag and put in a new spring (Wolff springs are always good) and a green follower, or tan Magpul follower. |
No, though I do use an after-market push-pin in place of the OEM Colt, large-pin, screw-type pivot pin. The take-down pin in the 'back' is OEM, though, I do use one of "those little red bumpers" to tighten-up the fit between the upper and the lower. Am going to try some other 30's that I have and see if that resolves the problem. Does anyone sell the green followers anymore----USGI ones? A couple of years back, green followers were for sale "all over the place---(on AR15)---now I can't seem to find them----only the magpul followers. |
Tweak, I'm not exactly sure what you mean by 'full, correct and complete'---it appears to have the M4-type feed ramps---two small ramps on either side of the 'bottom' ridge of the barrel locking nut(?). I originally had Pete-in-NH (legaltransfers) set it up for me----this is the first time I've had any problems with it, though----and it's likely had a good 4-5K rounds put through it since it was "converted" to M4'gery format/style. |
|
Look here under M4 Ramps. 4-5K rounds since the modifications? Changed ammo recently? Do you feel any binding when you slowly run the carrier forward with the charging handle? Strip the bolt from the carrier and slide the carrier into the upper, do you feel any binding as the carrier reaches the end of its travel? |
Tweak, I need to check the above items you mention. I'm gone, "up North" for the next several weeks, however, I will get back to you on this----probably send you an IM. The AR is up North, otherwise, I'd check it now. Will follow up to let you know what the "status" of this issue is. I appreciate your help and advice! CR |
AR Sponsor