What is your favorite powder? and what powder do you use with 165 and 180 300 wsm?
Does anyone use Vihtavuori 560 or Winchester WXR??
What powders are extreem as to temp?? Meaning what powders are not sensitive to temp?
Old Timer

I've had pretty go luck with R-19 with 165gr bullets but am trying some V-550 and it appears to shoot pretty good but need to do some more shooting and Chronograph that load. I only loaded afew in 180gr haven't tried another bullets yet. Had some luck with V-165 in 165gr bullets. I've got a custom and factory in 300wsm. H-4350 shoots pretty good also. Only problem so far just haven't found the right powder to work with more than one bullet weight not that you really need it in a hunting rifle. Our range is covered over the shooting area so haven't had any problems as to temp and powder. Saw some postings on R-22 some slower than other lot # but I haven't had that problem when using in the 300wsm. I tried the Win powder and didn't have any luck in either rifle. Some good information at shortmag.com. Good luck.

VithaVouri N550 is my favorite powder in the 300 WSM with 175 to 180 gr. bullets. I shot the throat out of the first 300WSM barrel with that load in F class matches. Just nothing else gave the velocity or the accuracy that N550 did. The second barrrel likes it just as well. If there is one powder that does it all pretty well in the 300 WSM with every thing from the 125 gr. bullets through the 210 gr. bullets it is H4350 EXT. If I could only have one powder for the 300 WSM it would be H4350.

RiverRat

Well, I just worked up loads for a new Model 70 chambered for the 300WSM. I did not try anything but 180 grain bullets. The plan was to get 180 grain Nosler Partitions to shoot well at 3050 fps so that the trajectory would be identical to the owners 7mm Rem Mag that shoots 160 grain Nosler Partitions at 3050 fps. These two bullets have virtually identical Ballistic Coefficients and starting them both at the same speed means identical trajectories.

Anyway, I tried RL 19, RL 22, IMR 4831, and N 560. With RL 19 and RL 22 I could not reach the velocity I wanted while sticking with safe loads in the Nosler Manual. With N560 I got GREAT groups (under a 1/2 inch) at 2900 fps, but up over 3000 fps the groups were nearly 2 inches. With a max load of IMR 4831 I was able to get solid one inch groups with 180 Noslers at 3052 fps.

My dad shoots a 7mm WSM and his favorite powder is N560 with IMR 4831 a close second. My buddy has a 270 WSM that shoots best with RL 19.

R F

I use nothing but Varget in my .300 SAUM.

My favorites with the 7wsm have been WXR, RL-19 & 22 with VN560 and MRP great for certain loads. BM

Bill

My results so far, 100 yard groups:

150-200 grain bullet weights: H414, Magpro, more than 1.5" groups on average, VN560 and H4350 1" or less on average

Best with 150's and 165's, Varget, closely followed by H4895
Best with 180's, H4350
Best with 200's, H4831SC
Best means .75" or less average with matchkings or NBT's.
H4350 is the most versitle, giving me good to great accuracy with all weights.

Yes, I like Hodgdon powders....YMMV! My rifle (M70 classic stainless) likes powders slightly faster than optimum in terms of pure velocity. Have fun!