Rell, Try Reloader 22. In my Ruger #1 it matched the factory Hornady velocity (with DGX bullets and Hornady brass) at around 83 or 84 grains. (I pushed it on to 90 grains and 2230fps in the #1 but that's not what you want to do.) Since it burns slower it might help with the crossing problem when you get to factory velocity. The other factor which you touched on is the crimp. Try pulling a bullet from a factory round and measure the inside diameter of the neck. See if your resized cases are the same inside diameter. Your answer may lie somewhere in the case neck tension details whether from the crimp or the case neck itself. A 4 inch composite group at 100 isn't anything to be ashamed of either.