Another interesting point regarding the use of Hammer bullets:
Most of the Hammer fans recommend using a Lee FCD to crimp in the bullets. They also recommend using magnum primers where you normally wouldn't need them. Both recommendations are to compensate for the rather low neck tension/interface.
I have tested quite a few loads with, and without, crimping. The outcome from using a FCD and Hammer bullets is far from predictable. I've seen some loads get better and some get notably worse. Erratic velocities were one of the things that I noticed on some loads. I have shot some very tight groups before the crimping idea got popular. Apparently, it works for some reloaders because it is almost universally recommended by Hammer shooters.
With regard to the magnum primers - the suggestion to use mag primers in all Hammer applications has been changing. Smaller cases are proving to work very well with standard primers. And recently, it has been determined that when loading for the 6.5PRC that you can load to much higher velocities if you avoid using mag primers. Mag primers apparently cause the loads to pressure up too quickly.
I like the Hammer bullets, but you really need to test the idiosyncrasies of loading this bullet for yourself. The blanket statements that are all over the web about Hammers haven't proven to be gospel in my tests.
