Elmer Keith and Phillip Sharp both get the credit on 357 mag and lets not forget Col Dan Wesson on the proecess. Kieth had been pushing 38SPC pressures for years and the real idea is solely his as he pestered Smith and Wesson, Winchester, and Remington to build a better 38 before he got together with the other 2. The .357 S&W Magnum (9x33mmR), or simply .357 Magnum, is a revolver cartridge created by Elmer Keith, Phillip B. Sharpe,[5] and Colonel D. B. Wesson[5] of firearms manufacturer Smith & Wesson, and Winchester.[6][7] It is based upon Smith & Wesson's earlier .38 Special cartridge. The .357 Magnum cartridge was introduced in 1934, and its use has since become widespread. This cartridge started the "Magnum" era of handgun ammunition.[8] The .357 Magnum cartridge has a positive reputation for stopping power.
http://en.wikipedia.org/wiki/.357_Magnum
45 colt was definitely Elmer Keith and I do duplicate and shoot many of his loads to include his 325 and 340 grain loads.
Dick Casull developed the 454 Casull which is not 45 colt. Most impressive work and I can agree it is a light step forward.
As for Kieth and the 357mag, could you please notify the more than 300 sources that is was only Sharp! Good luck!
Again I am with the 44, 45 colt, and 357 Mag in that order.