The .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.
.280 Remington
.280 Ackley Improved on the right
The Remington Model 760 Gamemaster is a pump-action, centerfire rifle made by Remington Arms from 1952 to 1981. The Model 760 replaced the Model 141 in the product lineup. Being fed by a box magazine freed the design to use more powerful rounds with spitzer bullets. It was succeeded by the Remington Model 7600 series.
DuPont ad for the Remington 760