So I have 2 15rd Grendel mags, i heard you could use 556 AR mags for Grendel. I tried to put the 6.5 follower in the 556 mag and it barely fit. I tried loading Grendel ammo in the 556 mag with the 556 follower and the ammo starts to tilt forward after about 10 rounds. I know there's 25, 26, 15, and 10rd Grendel mags, but if I can convert some of my 556 mags instead...