You only need to raise the bullet seater die and the powder/flare die by an 1/8". I do this with a spacer washer under these dies. No other adjustment is necessary.
A tight crimp is needed with a heavy magnum load in a revolver where the unfired bullets have a habit of pulling from the cases, like with a kinetic bullet puller, under heavy recoil, or if you like to cram them into a tubular magazine where they will push back into the case. Otherwise, I usually just set the crimp die to hold the bullets tightly enough that I can't move it in the case with finger pressure.
GM3 powder is one of my favourite .38 powders, but is made as a shotgun powder and very quick burning. I use 3.4gn for a light target load but I would be reluctanct to use as much as 7.2. The initial pressure rise must be rather severe!
Last edited by DesG; 04-08-2015 at 04:05 PM.
[I]DesG
Not known for making political comments.