Does anyone have any experience with this powder and the 300 wsm ? I will be shooting 175 gr JLK , and 168 Sierra bullets ?

If you check the shortmags.org forum , you will see a lot of peoples' results with Magpro in the short magnums. It is supposedly very similar to the factory powder that winchester uses to load the factory ammo. Many users have reported very high velocities for the given bullet weights, as well as good accuracy. It seems to trail only Reloder 19 in popularity, at least on that forum. I have no personal experience with Magpro and my .270WSM, but that is because I need look no further for my rifle than Vihtavouri N-165 and Nosler Accubonds and Ballistic Tips.

In my 300WSM it likes heavy (180+) bullets. It got erratic with 165/8's, and I didn't go lower. The high charge weights and velocities really show up in recoil. Accuracy is good, but not the absolute best in my rifle thus far. H4350 has that honor thus far, and VN560 is looking good too. Top loads are compressed, sometimes highly.

If you want the last 50 fps in your 300WSM, go for it. It routinely (and safely) hits 3025-3050 fps (180 gr) with safe pressures in 24" factory rifles. I second the reference to the shortmags.org web site to verify for yourself. Look at the forum under 'range reports'.

Have fun!

I worked up some loads with MagPro, 180gr Nosler Partitions in my Browning Bar 300WSM w/BOSS. 74.7gr had an avg vel. of 2823 with a 3/4 in. group, 76.3gr had an avg vel. of 2888 with a 1in. group. My BOSS was set at .5 for both loads. My next trip to the range I will try both of these loads and see if I can't srink my groups a little by adjusting the BOSS. I think my vel. are lower than most due to the BOSS giving me a much shorter barrel. I also did a load development with R-19 and the vel. were also lower.

Thanks for all the replies and keep them coming if anyone has anything to add. I'll add a little info for those looking for 300 wsm loads. To date my best load for my rifle has been as follows : Barrel is 24", 5.5 conture , fluted , 1/12 twist Kreiger. Best load to date 71 gr of IMR 7628 with 175 JLK bullet and Federal 215M primer at 3090 fps produces 1/2" 3-shot groups. I would like to find a powder / primer combo with a powder that is not as temperature sensitive as the IMR powder. So for H4831 and H4350 have not been as accurate as the IMR 7628.

I've got a Broughton 1/12 twist 5r barrel for my 300wsm. Finally settled on R-19. I tried N-165,h-4831,h-4350 plus afew other. I've been shooting mainly 150 and 165 gr Boattail bullets. I'm at 68.1gr/R-19 and 150 gr bullets alittle over 3100fps and 165 at 3058fps and today I shot some 180 gr with the same load but didn't chronograph. All three loads shot the same spot but will need to try some 200 and 300yd shooting with those loads. I think the 180 will be around 3000fps. I had the velocity over 3200fps with R-19 and R-22 with 165 gr bullet and got some pretty good groups all the way out to 300yds about the only problem I had was my first shot out was alittle low kind of figured it was me but afew trips to the range always had that shot low so dropped the powder back and took care of that. I got about 5 months before elk season starts so hope to have this rifle ready.

I have found 2 very good loads for my Browning stainless A-Bolt in 300WSM, both using Barnes bullets which I love,

First one is 59 grains of reloader 15 topped off with a Barnes XLC 168 grain. Shoots .5" on a good day. I know this is a fast powder for this caliber, but you cannot argue with success.

Second one is 71.5 grains of IMR 4831 topped off with a Barnes TSX 150 grain. This one has shot clover leaf groups but is always under .75".

My only question about both of these loads is I have not shot them in cold weather. More will be revealed in time.

Simdow

Tom,
Have you tried Ram-shot's new "hunter" good reports in Handloader shooting 165 Hor Interbond tikka 1/11 24" It is claimed that the powder is of course Belgium and designed for the short mags. I just picked up a pound and haven't made it to the range yet.
Old Timer