I played with it a little in my 270 WSM, it was way better than R17, showed less pressure signs with more speed. Accuracy was also better. It's on the winter list of powders to tinker with more. It showed promise though.
I am going to try it in 7mm wsm first. I was told by a guy at the range that he could not get any consistency out of his 270 wsm until he went to Magpro powder. Any help or information is greatly appreciated.
What I had was loading 2 rounds at 1/2 gr increments, I would have to check what I started with but when I hit the max with pressure signs the, same as my Retumbo, load I was pushing a 140 Berger at 3420 up from 3300 with good hint of accuracy. R17 max'ed out at 3260, and was spraying them out to 3 in.
Have any of you tried this powder in a 270Win? I saw velocities listed on the Accurate website but thought they may be a bit optimistic. They're showing 3234fps. Wondering if I'll like it any more than H4831SC.
I have tried Magpro in my 270 Winchester, with mixed results. I never was able to get the accuracy I was looking for so I gave up, despite the fact that I was getting more velocity than I had ever gotten from my Ruger 77. Many other people have gotten great velocity and accuracy with this powder so I may have given up too early.
The web site lists 65 grains as a Max load with a 130 grain Nosler BT bullet and they show the velocity at over 3200 ft./sec out of a 24 inch barrel. I was able to get 3100 ft/sec with a 130 grain Hornady bullet out of my 22 inch barrel. So if you are looking for velocity I think Magpro does offer it. Also some have said that this powder likes close to max loads and it is more accurate at near max loads. Maybe that is why I did not get the accuracy I wanted since I did not work up to a max load.