I'm working on a 6mm arc AR15 build, can't find any ammo under $2 per round and no brass in sight. Noticed grendel basic brass and a few folks saying grendel could be sized down to 6mm arc. I'm not having much better luck with finding grendel brass aside from the basic (no neck) version. Anyone experienced forming cases like this from basic brass that could give me an idea of what I would need to pull this off and how good of an end result i could expect? My searches left me with more questions than answers, figured I should just ask.