Hey guys I need help I have a 338 ultra mag putting a 31" shilen on it where to start my loads c.o.l. 4.088 so I've got alot of space please guys help me on powder and load thanks guys shooting a 300gn Berger hybrid
That long barrel plus brake is gonna cause you a bit of grief until you get used to that length.
Mine is a sporter weight carry rifle good to 1200 yds.
I stuff 101.5 gr of 50 BMG behind the 300 Berger. It shoots like and is as comfortable as a bench gun. The brake is only a Holland QD.
My heavy weights with the longer barrels are mostly for ambushing. Which is by far the most fun.
I'd also recommend Fed 215 primers not the GMs if you're going the Federal route.
It's been reported by those who should know and verified by me, at least with the lots I have that the 215 provides a bit more velocity than the match primer.
I shoot 90.0 grains of H-1000 with a 300 grain berger and it nets me 2830 fps. My friend shoots 91.5 of H-1000 and only gets 2700 different chambers shoot different. My barrel is a broughton 5C finished at 27 1/2 inches.