04-26-2022, 04:41 PM
I concur with others here. Go with the Lapua 6.5 Grendel despite the cost.
If you do neck up some 220 Russian brass to 6mm, make sure the case length fits your rifle's chamber. Because the headspace is so short, you might get erratic primer detonations. To keep the case head up against the bolt face, you'll need to seat the bullets out to just touching the rifling in your barrel (you'll need bullet comparators & a 6mm ARC case to establish seating depth). Another option is to size up to 6.5mm & then size the neck back down to 6mm just far enough that a false shoulder is formed to give you a temporary headspace location before fire-forming. It's a PITA to do all that work, but sometimes when Grendel brass is unobtanium, it's your only choice.
If you do neck up some 220 Russian brass to 6mm, make sure the case length fits your rifle's chamber. Because the headspace is so short, you might get erratic primer detonations. To keep the case head up against the bolt face, you'll need to seat the bullets out to just touching the rifling in your barrel (you'll need bullet comparators & a 6mm ARC case to establish seating depth). Another option is to size up to 6.5mm & then size the neck back down to 6mm just far enough that a false shoulder is formed to give you a temporary headspace location before fire-forming. It's a PITA to do all that work, but sometimes when Grendel brass is unobtanium, it's your only choice.
The trick is growing up without growing old. -- Casey Stengal