The .284 Winchester is one of a number of useful cartridges that should have proven to be extremely successful but didn't. Introduced by Winchester in 1963, the .284 was designed to squeeze .270 Winchesterand .280 Remingtonperformance from the new Model 100 autoloader and Model 88 lever action rifles. In order to squeeze such performance from a cartridge short enough to feed through those rifles, Winchester engineers designed the .284 case with a rebated rim and a body almost as large in diameter as that of the belted magnum case. The end result was a 7mm cartridge with about the same overall length as the .308 Winchester but with the powder capacity about the same as that of the .270 Winchesterand .280 Remington. Any difference in performance between the three cartridges is the stuff pointless debates are made of. For open country hunting of deer and pronghorn, the .284 loaded with the Speer130 grain spitzer at 3100 fps will do anything the .270 will do and it will do it in a short action rifle. Larger game calls for bullets weighing from 150 to 160 grains. H4831, H450, H4350, H414, IMR-4350, and IMR-4831are excellent powders for the .284 Winchester. 

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