I just recieved my rebarreled 700 rem. It is chambered for 300RUM 26 in barrel from ER Shaw. This is my first rebarreled rifle.
Does anyone out their have a rifle close to this one and what particular load does it shoot well. I want to
use 180 nosler partitions since I already have a box of those setting around. I also have for powder R 22
R L19, IMR 4831, IMR 4350 avaliable. Any sugestions would be appreciated.

I load for three of the.Try starting out at 90gr of RL25 or RETUMBO and work up.You wont be disapointed with either...

I like playing with AA-8700 From 100.8 grains to 113.0 grains and Remington 9-1/2 primer.

A friend in Texas swears by IMR-7828 From 76.6 grains to 94.0 grains and Federal 215 primer.

But since you don't mention either of those powders you might want to try:

RL-22 From 76.3 grains to 88.7 grains
Winchester WLR Primer

I really don't think the other powders you mentioned are that suitable for your combination.

Double what Boyde said, I stopped at 95gr of Rel 25 with a 180gr Swift Sccirrco for 3325fps. She'll take a little more, but it's plenty for what I want.

Retumbo, still not in this neck of the woods.

Reloader 25 works best for me.96 gr gives me 3375 and 1/2" groups out of my custom ultramag.