The 450 Alaskan was designed by Harold Johnson who was a resident of Cooper's Landing, Alaska. This cartridge was designed to meet the demands of hunters who wanted a lever action rifle that could deliver substantial energy and bullet mass for use against the largest and most dangerous of Alaskan game. Model 71's converted to this chambering are among the most prized rifles in Alaska. Ackley might have been the first to open the hole through the barrel and improve the chamber of the Model 71 Winchester. However, by Ackley's own testimony, Mr. Johnson's version of the 45 caliber 348 Improved is a better choice. 

This text is based on information from “Cartridges of the World”, Hodgdon reloading manual, the cartridge designer and/or own resources.