The .280 Remington, also known as the 7mm Express Remington, was introduced in 1957 for the Remington model 740, 760, 721, and 725 rifles. The .280 is based on the .30-06 Springfield necked down to accept 7 mm (.284in) bullets, with the neck moved forward .050in (1.27mm). Original loadings were 125, 150 and 165 grain bullet weights.
Read more about .280 Remington: History, .280 Remington Vs .270 Winchester, .280 Vs .30-06, .280 Ackley Improved, See Also