Hello all. This is my first post on this great forum.
I just recently bought my first AR15, a Bushmaster M4A3. I love it so far and have had no problems with the first 300 rounds. My question is regarding the last round in a magazine. I was under the impression that after the last round, the bolt would stay back so that a new mag could quickly be put in then the bolt release on the left side could just be tapped to chamber a fresh round(s). Mine does not do this. After the last round, the bolt is closed and I have to rack the charging handle again after a new mag goes in. Is this normal? As I said, I am new to ARs so am not really sure. I thought I had read somewhere that the bolt should stay open. Ideas? Sugestions? Thanks.
I tried to search but couldnt find anything,.