7MM SHOOTING TIMES EASTERNER
Handloader|October - November 2021
WILDCAT CARTRIDGES
Layne Simpson

The 7mm Shooting Times Easterner (7mm STE) was introduced in 1989 and it is formed from .307 Winchester brass. For those who do not know, the .307 Winchester is basically a rimmed version of the .308 Winchester and it was introduced in a Winchester Model 94 rifle with the rear of its receiver walls adjacent to the locking bolt thickened for reinforcement. The .356 Winchester on the same case was also introduced at the same time, and as you might guess, it is a rimmed version of the .358 Winchester. Since the two were developed for use in a tube magazine rifle, Winchester ammunition was loaded with flat nose bullets. I still have a pair of Model 94s chambered for those cartridges.

In early 1988, I sent a Marlin 336 in .356 Winchester to barrel maker Harry McGowen for barreling to the .307 Winchester case necked down for .284-inch bullets. My specifications included a 22-inch barrel with a 1:10 twist. Because the rifle would be used exclusively with a scope, I asked that the barrel not be dovetailed or drilled and tapped for open sights. The barrel Harry installed measures .920 inch at the receiver and tapers to a muzzle diameter of .640 inches. The bore quality is excellent and the rifling twist rate is 1:10. The rifle ended up weighing 7 pounds. Immediately upon its return from Harry, I used George Miller’s two-piece Control mount to attach a Bausch & Lomb Balvar 1.5-6x scope, and after surviving many hard knocks and some pretty awful weather through the years, the scope is as good today as it was back then. The scope and mount increased the weight of the rifle to 8 pounds, 3 ounces and it proved to be quite accurate.

On my first go-round with the 7mm STE, the case was formed by simply necking down the .307 Winchester case with no other change. My plan was to load it to the same chamber pressure as the .307 Winchester, and when experiencing sticky case extraction prior to reaching that level, I recalled an experiment performed by P.O. Ackley. He illustrated how a reduction in case taper reduces thrust against the breech bolt of a rifle because the case has more of a tendency to grip the wall of the chamber during firing. This assumes the absence of oil or other lubricant on the chamber wall or on the cartridge case.

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