308 LR PMAG Mag Length?

I'm getting 2.814, I've got some 168's with COAL 2.790 in one right now and they have some room. The front of the mag doesn't look square to me, might be an extra .005 in there where the tips actually sit.
 
M2 or M3? Seems like the M3's will feed a slightly longer COAL than the M2's.
I sold a bunch of M2 20 rounders because I couldn't get them to feed the M118LR I have. Some of the rounds have a COAL of 2.83+.
So far the M3 10 rounders have been 100% with the same ammo.
 
M2 or M3? Seems like the M3's will feed a slightly longer COAL than the M2's.
I sold a bunch of M2 20 rounders because I couldn't get them to feed the M118LR I have. Some of the rounds have a COAL of 2.83+.
So far the M3 10 rounders have been 100% with the same ammo.

I also had a little trouble with the new pmags and older m118lr. I had some 07 head stamp that was just barely too long to feed reliably but 08 head stamp fed perfectly. Go figure.