I'm real keen on many of the Ackley Improved cartidges - I guess they are not really a "wildcat" since you can shoot factory ammunition in them while fire forming. P.O. Ackley's shop was not very far from here and he taught at the Trinidad College. I currently own a .22-250 Ackley, a .25-06 Ackley, and .270 Ackley. All are the 40 degree version. I have also built them in .223, .243, 6MM Rem, .257 Roberts, .280 Rem, .308 Win,30/06, and .338-06. All of them will deliver around 200 fps more speed than the parent caliber - but the biggest advantage, IMO, is that the cases shrink a little when fire forming; and then don't really need trimming after that. I hate case trimming. Roscoe