7 mm STW

The 7mm Shooting Times Westerner (7mm STW) is a magnum rifle cartridge introduced in the late 1980s. It was developed by Layne Simpson, a well-known gun writer and shooting enthusiast, who designed it by necking down the venerable 8mm Remington Magnum case to accept 7mm (.284 caliber) bullets. The intention was to create a high-velocity, flat-shooting cartridge for long-range big game hunting. Initially, the 7mm STW gained traction among handloaders and custom rifle builders before Remington standardized the cartridge in 1996, adding factory rifles and factory-loaded ammunition to the market. Since its inception, the 7mm STW has built a reputation for velocity and downrange performance, especially among North American hunters seeking a cartridge with extended range and energy.

For reloaders, the 7mm STW offers a unique combination of case capacity, velocity, and ballistic efficiency. The cartridge is especially popular for those looking to push the performance envelope beyond traditional 7mm magnums like the 7mm Remington Magnum. Because of its large powder capacity, the 7mm STW can deliver higher velocities with comparable bullet weights, which means flatter trajectories and less wind drift at long distances. These characteristics make it an attractive option for custom load development. Reloaders can customize their load recipes for specific rifles and hunting scenarios, taking advantage of the cartridge’s high velocity and the wide range of premium 7mm bullet options. Careful attention to case preparation, powder selection, and precise measurement is required, as the cartridge operates at relatively high pressures, necessitating quality brass and robust reloading practices.

The 7mm STW is primarily used in long-range hunting applications due to its excellent ballistics. Its high velocity and ability to carry energy efficiently downrange make it ideal for open country pursuits where long shots on game like mule deer, elk, and pronghorn antelope are common. The cartridge is also suitable for larger species such as moose, though it requires careful bullet selection for adequate penetration at extended distances. The flat trajectory provided by the 7mm STW enables shooters to better compensate for range estimation errors, enhancing ethical shot placement. While not as common for benchrest or competitive shooting as some other cartridges, the STW’s accuracy potential attracts long-range enthusiasts who reload their own ammunition and prioritize ballistic performance.

When it comes to bullet weights, the 7mm STW’s versatility shines. Reloaders commonly choose projectiles in the 140 to 175 grain range. Lighter bullets, such as 140 or 150 grains, excel in varmints or medium game and maximize velocity up to or exceeding 3,400 feet per second. Heavier bullets, such as 160, 168, or even 175 grains, are preferred for larger game due to higher sectional density and better penetration, with velocities often in the 3,000 fps range or higher with careful handloading. The large case capacity allows for flexible powder choices, with slow-burning powders like Hodgdon H1000, IMR 7828, and Retumbo often performing well. The cartridge’s long case does require a magnum-length action, and its performance can be maximized with barrels of 26 inches or longer to make full use of its powder volume and realize advertised velocities. Cases can be formed from 8mm Remington Magnum brass if factory brass is scarce, offering reloaders additional flexibility. Altogether, the 7mm STW remains a compelling choice for reloaders seeking magnum-class performance and long-range hunting capability in a proven 7mm platform.