Well I took her out shooting yesterday. Same mags, ammo, etc. Put about 200 rounds through it, loading the mags from full, to twenty, to ten, and to even only 5 rounds at a time. And after rapid firing, double tapping, and triple tapping through all the mags I didn't have a single malfunction! All rounds fired were extracted like they were supposed to and there were no more feed jams caused by the straggler left in the chamber. All I did was add the spring kit from BCM, so if anyone reading this ever runs into the same problem I described, you should have your solution here. And for the record I used the new spring with the o-ring supplied and haven't had a ripped off case head yet. Also for the readers from before thank you guys for all your input and opinions.
the black o-ring and heavy spring kit comes installed with LMT and BCM bolt-carrier group kits. just picked up a new LMT bolt carrier group from matt-d tactical for my new CDD m4LE build this week. i fried about 350 rounds of mixed ammo this week between t-storms --not a one hiccup. slurpy smooth to boot.
glad it is working for you.
on a bushmaster i all ways check the gas-key stake to be on the safe side as well. some times they will work a bit loose with use and cause a short stroke or two.
the AR series can be a dependable weapon -- you can download army manual TM-9-1005-319 23&p from some of the AR sites it has about all you need to know to make the m4 run--trouble shooting , repair, assembly it is all there.