I have a problem with my AR 10 T after the gun fires the first round it jams the second against the bolt catch.  This isn't the problem that is concerning me.  The real problem is the projectile is being compressed into the case. Has anyone had this happen to them?  Ammo is Black hills 308 168 grain BTHP moly coat.

I don't fully understand what you're saying.

1. Does the rifle jam or is the round fed and chambered but just deformed.  The bolt catch is rear of the magazine, hence the rounds.

2.  Or does the magazine jam the rear of the round up, and into the bolt catch?

In any event it sounds like a magazine problem.

Does this happen with all the magazines that you have?

It's probably the ammo you are using. Unless your AR-10 was specifically designed to use bolt action 168gr match, I would expect problems. Most semi-automatics are designed to use a specific round. Does your AR say .308 or 7.62 on the reciever? You know that the case length is slightly longer on the 7.62 right?

I remember recently looking at a 147gr 7.62 Nato and a Black Hills 168gr Match side by side and they weren't the same overall length. The 168gr slug was quite a bit longer than the standard 150-147gr.

It happens with all the mags.  It happened four times in the same day.  I was thinking it might be the neck of the shell being too loose and the projectile is just resting in there without any compression.