From Wikipedia, the free encyclopedia:
"The .284 Winchester is an example of a commercially rather unsuccessful cartridge. Introduced by Winchester in 1963, the .284 Winchester was designed to squeeze .270 Winchester and .280 Remington performance from the new Model 100 autoloader and Model 88 lever action rifles.
The end result was a 7 mm cartridge with about the same overall length as the .308 Winchester but with the powder capacity about the same as that of the .270 Winchester and .280 Remington.
At one time the Savage Model 99 was available in .284 Winchester, and Ruger produced a small run of Model 77 rifles in this caliber. Surprisingly enough, Ultra Light Arms now builds more Model 20 rifles in .284 Winchester than all other calibers combined. Which probably tells us that only those high country hunters who are willing to pay for a 4-1/2 pound sheep rifle appreciate what the .284 Winchester has to offer.
For open country hunting of deer and pronghorn, the .284 Winchester loaded with the Speer 130-grain (8.4 g) spitzer at 3,100 ft/s (940 m/s) will do anything the .270 Winchester will do and it will do it in a short action rifle. Larger game calls for bullets weighing from 150 to 160 grains (10 g). H4831, H450, H4350, H414, IMR-4350, and IMR-4831 are excellent powders for the .284 Winchester.
These ballistics make it clear that the .284 Winchester is as good as the .280 Remington with the same weight bullet. Of course the short, handy mountain rifles for which the .284 Winchester seems best suited seldom come with 24 in barrels. Aside from Winchester, no other major company has ever loaded factory ammunition for the .284 Winchester.
The .284 Winchester is not popular in Europe, where it competes with the 7 x 64, to which it is almost ballistically identical. When compared to the .284 Winchester the 7 x 64 has a lower C.I.P. maximum allowed chamber pressure and as a European 7 mm cartridge has a slightly larger bore. European 7 mm cartridges all have 7.24 mm (0.285 in) grooves Ø diameter. American 7 mm cartridges have 7.21 mm (0.284 in) grooves"
284 Winchester. (2009, January 14). In Wikipedia, The Free Encyclopedia. Retrieved 23:31, March 19, 2009, from