What's your favorite .30 WSM or RSAUM powder for 165gr or 180gr bullets? (i.e Magpro, H4831SC, RL19, RL22, VV160, etc.)?

I've used RL 19 and H4831 with excellent results.

Currently getting good results with IMR4831 and a 180 Partition.

Without a doubt, my best luck has been with H4831SC. I had to go over max in my rifle to shrink groups with a 165 H-interbond. I won't say how much over. This was with chrongraph readings AND keeping an eye on pressure ring measurements. Max on the data sent me by Hornady is 69.0 it showed the group starting to shrink, so I went higher. It ended up at .467 and the lowest extreme spread and SD of ANY load I've tried.

.300 WSM
165's - RL-19 From 61.7 grains to 72.5 grains
Winchester WLR Primer
180's - RL-19 From 61.3 grains to 70.5 grains
Winchester WLR Primer

.300 RSAUM
165's - W-760 From 56.6 grains to 63.5 grains
Remington 9-1/2M Primer
180's - H-414 From 57.0 grains to 63.0 grains
Remington 9-1/2M Primer

In my WSM, with 165 and 180 Hornady Spire Points, W760 worked best for me.

R-WEST

Many will think reloder 15 is a little fast for the 300wsm but my Browning loves 59 grains of it with a Barnes 168 xlc on top.
Always under 1 in and on a couple of occasions as small as 1/4 in. This is the best powder I've found for my gun shooting Barnes 168's, Ive had ok results with Reloader19 also.

It doesn't surprise me that RL 15 works very well in the 300 WSM. I have had very good luck with powders that would seem fast for a 30 caliber magnum. IMR 4064, Varget, and N540 work very well with the 150 gr. bullets, and the 4350 class of powders work well with the 175 to 210 gr. bullets. If I had to chose just one powder for the 300 WSM it would be H 4350 EXT or N550, RL 19 would be next in line.

I have also found that standard large rifle primers have worked much better for me than large rifle magnum primers have. IMHO magnum primers are just not needed in the 300 WSM. In my testing all they did was give higher pressures, less accuracy, and higher extreme velocity spreads regardless of charge weight.

I have put over 1500 rounds through my 300 WSM rifle that I had built for F class competition in the last 1 1/2 years. It is now being rebarreled with a 3 groove Lilja for competition next year. If this barrel shoots as good as the last one I should have a good season if I can do my part. I really believe the 300 WSM is keeper.

May I be half the man my grandson thinks I am.....RiverRat