7mm Remington Magnum

The 7mm Remington Magnum rifle cartridge was introduced as a commercially available round in 1962, along with the new Remington Model 700 bolt action rifle. It is a member of the belted magnum family that is directly derived from the venerable .375 H&H Magnum. The original purpose of the belted magnum concept taken from the .300 H&H and .375 H&H, was to provide precise control of the head-space, since the sloping shoulders, while easing cartridge extraction, provided poor head-spacing. Improved cartridge extraction reliability is desirable while hunting dangerous game, which would be of concern when needing a fast follow up shot. The 7mm Rem is based on the commercial Winchester .264 Win Mag, .338 Win Mag, and .458 Win Mag, which were based on the same belted .300 H&H and .375 H&H cases, trimmed to nearly the same length as the .270 Wby Mag.
On its introduction, the 7mm Rem. Mag. substantially usurped the market share held by the .264 Winchester Magnum...