+1 on PRI 6.8 mags. They accept an OAL of 2.300" with a few thousandths to spare. Good if your running 88ELDM because they are 1.24" long and even at 2.3" they are jumping a bit in a SAAMI chamber/throat.
I have 2 - 10 rounders and a 15 rounder. Work and function flawlessly out of the bag.