I just got my first AR15. Since I live in CA I am forced to get a FAB 10 lower reciever. When I have the fixed 10rnd mag filled the upper reciever will not close all the way without using a lot of force. And when it does it is impossible to pull back on the charging handle. If I load the magazine with 9 or less rounds the gun functions flawlessly. Its as if the mag will not allow the upper to compress the rounds in the mag at all(if its supposed to do that). What do you guys think my problem is? I will not continue to just load 9 or less rounds its too many as is. What do you think I could do with out having to send it back to the manufacture?

Thanks for your time and help I really appreciate it.

- William

It kinda blows but it's a very normal thing to have happen. See when it positively has to stop at ten rounds, well that doesn't leave any room for the follower and spring to compress when closing the upper. They don't want anybody sneaking in that one extra. Bushmaster's ten round detachable mags have the same kind of problem, just about any lawsuit aware company making post ban mags do that to protect themselves.

I don't know how hard it would be to remove the mag or if at all possible with tools even, but if you could remove it, open it up, and see if you can file down just a tad what ever it uses to limit it's travel, and try to gain about one eigth of an inch of travel so it closes and cycle on the tenth round.

-Mark