Ejection Problems on Bushmaster M4
My carbine (Bushmaster M4 14.5 perm Phantom, a LaRue 13.2 rail, and an Eotech 512, with all internal parts as they were from the factory) has shot over 2,000 rounds without a failure prior to this incident. However this time I was shooting Guatemalen ammo, the new shiny stuff that AIM is selling now.
The problem happened when using a British Steel mag with green follower. It only happened twice (out of 270 rounds fired total) and both times with the same mag. It occured when loaded with just 5 rounds, and when laoded to full capacity.
The jam can best described as an FTEj. The spent round is stuck with the rear against the bolt face, and the front stuck up in the charging handle channel. The bolt is also in the process of stripping a new round off the mag but cannot go farther due to the spent case obstructing its forward travel.
I've looked and looked and searched, but haven't found any problems similar to mine. AFAIK, the guatemalen ammo has been totally reliable in other shooters' rifles.
I was wanting to know what may be causing the problem (weak ejector spring, a poor extractor spring, etc) and what parts I may buy to alieviate it, or if it is ammo related, although I'm not sure how ammo could cause a failure like this.:confused:
At the risk of reviving a dead thread
I was shooting my rifle this weekend and had about 7 or 8 FT Ejects. Upon examination of my bolt, the ejector seemed fine with good spring tension, the extractor rim is in good shape, but dirty (shame on me), and my bolt gas rings were worn, not to the point that they wouldn't support the carrier weight if stood on the bolt face, but 2 of the 3 were obviously missing pieces/excessive gap. The carrier gas key is tightly staked down and gas tube is in good shape.
My question is could worn rings cause this FTE? I have since cleaned the rifle well and replaced the gas rings with the one piece coil type, I have also installed a new extractor spring, crane, and o ring upgrade kit just to be on the safe side. Any answers or advice appreciated.