Can you shoot 6mm ARC ammo in a 6mmAR barrel ?

[Pig_Popper]

The shoulder is .02-.03 setback on the case but the neck size (loaded) and shoulder dimensions are the same.

It’d be an interesting way to fireform 6mmARC brass to 6 Grendel chamber.

What say y’all ?

Safe ....?

[grayfox]

You'd probably get more opinions from the Grendel forum...
But I wouldn't do it, 0.020 is too much stretch.
Remember the discussions on using a 0.136 bolt in a 0.125 cut chamber... that's only 0.011 but was dangerous.
6Arc chamber datum is 1.190; Grendel is 1.220-1.230
You're looking at 0.035 stretch, which will all come from only a portion of the brass case wall.........

[StoneHendge]

It would probably work, but for what your trying to do its risky when you reload it. Whitley justifies running the high pressures he runs due to the strength of Lapua brass and you'll end up with slightly thinner Hornady brass.