Mt AI,
You seem to have a good handle on the project. I concur with CJF's comments, not only does less working of the neck mean longer case life as he said, but leaving the rest of the body" fireformed" will precisely center the cartridge in the chamber. Shooting the second shoot very quickly after the first, as you are correctly doing, sometimes makes it hard to determine whether the bullets are crossing or shooting wide. You can sort this out by using 2 targets side by side, shoot the right barrel on the target then quickly shoot the left barrel on the left target. Then after cooling, repeat the process. Once the correct number of pairs have been fired, place one target on top of the other and mark the bullet impacts on one target through the holes in the other one. This prevents delaying the second shot in a pair to locate the first. If your bullets are sized to .446" and "fall" through the fired neck, you might try them "as cast" (pan lube or by hand) and see how they work. Once you determine what limit you will put on your shots, you may want to start regulating the loads at a distance appropriate to that limit rather than 30 yards.
Mike
