I am looking for a 44 magnum load I can use in my 629-1 with a four inch barrel that won't jump the crimp. The bullet I am using is an RCBS 250 that weighs out with my alloy at 265 grains. The load I tried a few minutes ago was 15.4 grains of 2400. I tried two cylinders of this load using Winchester brass that had been fired several times, and after I fired the first five rounds, and I checked the remaining cartridge in the cylinder the crimp held. But when I loaded the cylinder with Starline brass the last round jumped the crimp. When I loaded the cylinder with IMI brass the last two cartridges jumped the cylinder so far that it tied up the gun. Both the Starline and the IMI brass has been loaded several times. All of the loads were seated to the same depth, and as far as I could tell by eye and feel the crimps were the same. I know 24 rounds is far from enough to create a valid sampling, but I wonder if this emerging pattern I am seeing that the Winchester brass performs properly and the other two don't is valid, and if it is does anybody know why.