7 mm STW Load Data

Caliber Overview

The 7mm Shooting Times Westerner (STW) has a unique and storied place in the landscape of high-powered rifle cartridges. Developed in the late 1970s and officially introduced in 1989, the 7mm STW was the brainchild of Layne Simpson, a prominent gun writer and ballistician. This magnum cartridge was designed by necking down the venerable .8mm Remington Magnum case to accept 7mm (.284 inch) bullets. The purpose behind the design was to push the performance envelope beyond the already-popular 7mm Remington Magnum, offering higher velocities and flatter trajectories for long-range shooting. After its debut in the pages of Shooting Times magazine, the 7mm STW gained significant traction among hunters and long-range shooting enthusiasts, eventually earning SAAMI approval and factory chamberings in several production rifles.

The 7mm STW found its niche primarily in long-range hunting and shooting applications. Its powerful ballistics and flat trajectory make it exceptionally suited for hunting big game in open terrain, where shots beyond 300 yards are not out of the ordinary. With its high velocity and energy, the 7mm STW delivers the precision and terminal performance needed for clean ethical kills at extended distances. While not as common as the more standardized cartridges in North American and African hunting circles, it is especially revered by serious hunters targeting mule deer, elk, or even larger North American species in open basin or mountainous regions. Additionally, long-range target shooters have also adopted the cartridge for its accuracy and ability to buck wind over distance, bolstered by the modern advancements in 7mm bullet design.

For reloaders, the 7mm STW provides an excellent platform for experimentation, thanks to the variety of high-ballistic coefficient (BC) bullets available in the 7mm diameter. The cartridge excels when loaded with bullets in the 140 to 175 grain range, with the heavier projectiles—such as 160, 168, or even 175 grains—being highly favored for long-range performance and retained energy. These heavier bullets maximize the cartridge’s potential when shooting at distant targets or pursuing larger game. With its large case capacity, the 7mm STW achieves impressive muzzle velocities, sending 140-grain bullets upwards of 3,400 feet per second and 160-grain projectiles at over 3,200 feet per second, depending on barrel length and loading parameters. The cartridge’s case geometry, based on the .8mm Remington Magnum, ensures reliable feeding and extraction in high-quality bolt-action rifles, an important consideration for both hunters and competitive shooters alike.

The reputation of the 7mm STW as a long-range powerhouse comes not just from its velocity, but also from the excellent selection of 7mm bullets, many of which offer exceptional sectional density and ballistic coefficient. This allows shooters to pick bullets that resist wind drift and maintain velocity at extreme ranges—a crucial factor for both ethical hunting and precision target shooting. Reloaders will appreciate the flexibility the cartridge affords, with numerous bullet weights and profile options from leading manufacturers, making it possible to tailor loads to specific game animals or long-range disciplines. As a magnum cartridge, 7mm STW also generates significant recoil and requires robust actions and quality optics, but for shooters willing to invest the effort in load development, it rewards with superior downrange performance.