Help:AR short stroking

[m*o*a]

Bushmaster had a bad run of barrels, with some of the gas ports being too small, causing what you call short stroking. Have a gun smith enlarge the gas port, or send it back to Bushmaster to be fixed.

[Kaiser.Shooter]

Bushmaster had a bad run of barrels, with some of the gas ports being too small, causing what you call short stroking. Have a gun smith enlarge the gas port, or send it back to Bushmaster to be fixed.

right (bad barrels run), this is what I was talking about!

[wilsonpenfam]

I have a Bushmaster XM15 E2MS, it is a A3 flat top with a 20 in bbl, and I have been having problems with it short stroking. After the charging handle is pulled all the way back and dropped, a round is chambered, then it fires fine. The bolt carrier goes back and the shell is ejected. However, the bolt carrier doesnt go back far enough to get behind the next round in the magazine and chamber it. So consequently the bolt slides back forward without the next round.

I have tried many different types of ammunition(handloads, factory loads, 45gn, 55gn, 68gn,ect) I have also tried different magazines and replaced the gas tube and I have still been having the same issue. It has also been cleaned and lubed(not over lubed though) and I have still been having the same issue. Does any one have any ideas or suggestions for me?

I tried to give as many details as possible but if you have any other questions feel free to ask.

Thanks

I had this same problem with 2 bushmasters. I replaced the extractor spring and insert with a new spring and a BLACK insert instead of the BLUE. was told to do this by an army marksmanship unit gunsmith and it worked great after that. that is the cheapest place to start. hope it works for you.