Re: Winchester 780 powder
I see this is an old post but thought it might be helpful to someone if I answer it.
I am using the 780 in a Ruger 270 Winchester bolt action with 22" Barrel using 165 gn Matrix Bullets. I have worked up loads in several powders including Magpro, Ramshot Magnum, RL-25, H-1000, IMR 4831 and probably a couple others I have forgotten. The Mappro worked well up to the high 2700 fps range and was consistantly accurate but I was able to get consistantly accurate loads above 2850 FPS with the Winchester 780 so that's what I'm going with. I use a GM215M primer though a 210 would probably work for the same velocity using another .1 gns of powder. It appears to be slower burning than the IMR 4831 but faster than the other powders I mentioned above.
I started out looking for a suitable Elk load for my hunting friend for use in his 270 win assuming the 165 grain bullet would probably not stabilize but willing to give it a try. It did stabilize even a sea level so just kept working up loads to see where I could take this. This bullet has close to a .7 BC and excellent SD so ought to do the job quite well out to 500 yrds or so.