.280 Remington, also known as the 7mm-06 Remington and 7mm Express Remington, was introduced in 1957 for the Remington model 740, 760, 721, and 725 rifles.
SPECIFICATION OF 280 REMINGTON
.280 Remington is based on the .30-06 necked down to accept 7 mm (.284 in) bullets, with the neck moved forward .050 in (1.27mm). The neck was deliberately moved forward to prevent chambering in a .270 Winchester rifle, as firing a .280 round in a .270 rifle could cause the projectile to get stuck in the barrel or rupture the barrel due to excessive pressure.
Firstly, 280 is capable of generating slightly higher velocities in heavier bullet weights (150 grains and above) than the .270 Winchester due to a marginally greater case capacity. However, the ballistic coefficient of equal-weight bullets favors .270 caliber bullets over 7mm (.284) bullets of similar design. In the heavier bullets (150 grains and above) of similar design, the .280 Rem has a slight edge in muzzle energy.
Secondly, 280 Rem long-range velocity and energy due to the 270’s higher ballistic coefficient according to Federal’s ammunition catalog. There are also many more factory loads available for the .270 Winchester over the .280 Remington at a lower price point due to the .270’s much greater popularity.
More to that , 280 is capable of developing energy nearly equal to the .30-06 Springfield, but with lighter bullets having a better ballistic coefficient. The .30-06 produces more energy than the .280 with bullets heavier than 180 grains, though .284″ 175-grain bullets have a high sectional density of .310, compared to the 30-06 180-grain bullet with a moderate sectional density of .271. The .280 is suitable for hunting any game in North America with good shot placement.