question

[ldvn12]

which would u rebarrel mark v 338-378 to a 30-378 or a 378 wby for big game long range and accuracy

 

[Varmint Hunter]

I don't see the 30-378 as having enough edge on a 300RUM to make the BIG difference in ammo/brass cost worthwhile.

That case needs plenty of bullet weight to make sense. I'd go 378WBY.