Re: 30-378 acurate loads
If you want to shoot long range for that caliber use a bullet that will take advantage of its powder capacity, otherwise you may as well have a 300 WBY.
Start at 210 grs and more. I shoot 240 SMK's in my 30-378, 210 Berger's in my 300 WBY.
Start at around .030 off the lands and fine tune for accuracy. The Bergers will probably want to be closer.
USMC Scout Sniper 88-94
Instructor 1st. Mar. Div. SS school 91-94