Solitary Man

Didn't get to play around much with my new .300 Win this year before the scope went south. Right now I'm waiting on the scope to be returned. Before the scope wentbad, though,I was having very good luck with RL22. Accuracy was excellent with 165 gr. Ballistic Tips and Fed 215M's. When I get the scope back I'm going to start back withthe same powder and 180 gr. Sierra Matchkings.

I think 4831sc should be an excellent powder also. It works very well for me in my 7mm mag.You just gotta try different combos and see what works best in your rifle.

cataway

best powder R 22. use 180gr bullets ,thats what your gunsbeen chambered to use.

backyardreloader

I have found that alot of your big bore guns like the slower burning powders. I whould try some loads with imr 4350. im pretty sure you will find that this powder will work and perform very well. i am using 73.6grs, with the hornady 150gr innerbonds. still tuning a little but real close. good luck!

Superpig

H4831SC is a good place to start. It's one of the better powders to use in the 300 Win. Mag. As far as the best powder I think if you took a poll that RL22 would probably win out especially with 180 gr. bullets. If you like the 200's you can try RL22, RL25, & H1000. Out of a 26" barrel 300 I reached a little over 2900 fps with good accuracy with RL25. This is one particular rifle I sold an have regretted it ever since.