338 ultra where to start

[mcharger440]

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

[royinidaho]

I"m an odd ball out on this one.

Most use Retumbo and H-1000.

I tried 50BMG and lucked out. Great velocity great accuracy. 300 Hybrid @ 2735 out of a 26" sporter barrel.

Ya can't get enough 50BMG in there to hurt your self. I think the case would swell not allowing chambering before things were in danger. Seriously though, start low and work up.......

[mcharger440]

I do appreciate the reply as I said I have no idea this is an odd setup I may just have to give 50bmg a try I mean my barrel finishes at 31" I might get it pretty fast

[royinidaho]

I see nothing odd about it.

The 338 RUM is a great cartridge.

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.

Good luck.

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.

[D.Camilleri]

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.

[mcharger440]

D. What barrel does your friend have

[D.Camilleri]

My friend's barrels are factory Remmy 26"