just bought a winchester m70 300 wsm and was wondering if anyone was reloading for it yet, if so whats working the best. probably a nosler partition but not sure on powder

Accurate Arms has a powder designed specifically for the short mag family of cases. The powder is called MAGPRO. I have seen a few fellows at the range that rave about the velocity and accuracy they get using this powder. On bullet selection any controlled expansion bullet should work well. Using MAGPRO in a 24" barrel should garner 2950-3050 fps with a 180 gr. bullet. I would look to the Nosler Partition in 180 gr. or the Barnes X in 165 gr. I would stay away from the ballistic tip and go with the AccuBond if you are looking the a polymer tip bullet. I think the lightest bullet weight I would consider for hunting would be the 165 unless you are planning on shooting Pronghorn at long distance then the 150's should be fine.

If your looking at 180 partitions or ballistic tips H4350 and 65.5 Fed 215 primer is nonfallible in most 300 wsm's i have loaded for..work up to it slowly. Reloader 22 is supposedly another good powder have not tried it yet. .

i've chronographed all the wsm calibers they all met are exceeded published speeds with factory ammo.these are the only cartridges i've seen do that,i don't own one so i haven't done any reloading i'm curious is it hard to bet the speeds for factory rounds rolling your own.they load these things hot.

Try the reloading forum, you will probably get more replies.

I've had people tell me you cant beat the factory loads on the 300wsm, but i have reloaded for a while now and this is my first magnum rifle so i want to see what i can do with reloads. thanks everyone

You can match the factory loads pretty easily and in some cases beat them. I haven't used Magpro yet on the 150 grain bullets but it supposedly matches ballistics as well when used. Try WWW.Reloadersnest.com

I have a Win mod 70 in 300WSM & have worked up 2 different loads that are equal to or slightly better than factory. The first is with a 180 gr fail safe with RL 19. I killed Bison, black bear & mule deer with this load. The second is a 165 gr Swift Aframe also with RL 19. I took this load on a dall sheep hunt but wasn't fortunate enough to kill one. I use Norma brass & CCI mag primers. While working up loads for this my gun seems to shoot better as the loads get hotter.

I just started reloading the .300 WSM also. I am loading Win brass CCI 250 primers IMR 4350 powder and Sierra 165 SBT. Sierra says starting load is 58 grains of 4350, max is 66gr. chrony 2950-3150. I got .6" group of 6 rds at 100 with the 65 gr load and .5" with the 60 gr load. This was out of a Savage Mod 11
Havent loaded any other brand of bullets yet. let me know if you find a better one!