The 470NE operates at about 37Kpsi and will drive a 500 gr bullet to 2150fps. The 450 ackley will drive a 500 gr bullet to over 2400fps and the 458 Lott will do about 2300fps with the same bullet weight. Both the 450 Ackley and 458 Lott operate at 55-60Kpsi and thus are unsuitable for nearly all double rifles. the 470NE is a rimmed case designed for double extraction and the Ackley and Lott are belted mags derived from the .375 H&h case. Both the Lott and Ackley offer a tremendous increase in performance over the 470NE ( although this cartridge has a tremendous reputation).-Rob