I haven't been able to locate a reasonably priced P.O. Ackley book(s). I know some of the Impoved cartridges don't give much extra bang for the buck. Would you rate the best Improved cartridges that give the best improvement over their standard counterpart? Are the best the 22-250, 30-30, 257 roberts, 223? If you can rank them accordingly, as many as you want to, I would appreciate it or if you have a comment or commentary on the cartridges or their effectiveness, etc. I would like that as well.