284 Winchester ammo sports a 7mm bullet and is an attempt to achieve the performance capabilities of the .270 Winchester and .280 Remington in a smaller package. Developed by Winchester in 1964, the sharp-shouldered (steepest shoulder angle ever produced by an American arms manufacturer) little round fits into a compact magazine no longer than a .308.
.284 ammo got off to a slow start although it has found some resurgence among long range and F-class shooters. The inherently high ballistic coefficients and sectional densities of the 7mm bullets help the round to produce admirable accuracy. Although the round was initially developed for short action, lightweight rifles from Winchester like its Model 88 and Model 100, which had shorter barrels, its full potential is best brought out by at least 24 inch barrels.