Winchester introduced the .351 WSL in 1907 for their Model 1907 Autoloading Rifle. Winchester autoloaders of the time could not accommodate the higher pressure and back thrust of more powerful cartridges, so the .351 Self-Loading cartridge was designed for the existing Winchester action. Naturally, this resulted in performance compromises and the .351 WSL is not nearly as powerful as the .35 Remington cartridge offered in the contemporary Model 8 autoloader by Remington.

The .351 WSL is based on a semi-rimmed, straight-sided case 1.380" long that uses small rifle primers. The rim diameter is .407" and the head diameter is .380". Cartridge overall length is 1.90". Jacketed bullet diameter is .351", not the standard .357"-.358" used by modern .35 caliber cartridges. Size cast bullets to .352". The maximum average pressure should not exceed 39,000 psi.

Winchester offered .351 WSL factory loads loaded with 180 grain jacketed soft point (JSP), round nose bullets. The muzzle velocity was stated to be 1850 fps and the muzzle energy 1370 ft. lbs. from a 20" barrel. Accuracy was always regarded as fair at best from Model 07 carbines.

Modern reloaders will have trouble finding .351 WSL brass and .351" JSP bullets. Lead bullets can be case from #2 alloy using Lyman mold #350319. These bullets weigh 171 grains with a .348 caliber gas check. According to the 45th Edition of the Lyman Reloading Handbook, IMR 4227 proved to be the best overall powder for the .351 WSL.

Using a 180 grain JSP bullet, Lyman data shows a starting load of 17.0 grains of IMR 4227 for a MV of 1400 fps. The maximum load is 19.5 grains of IMR 4227 for a MV of 1751 fps.

With a 171 grain cast lead bullet and IMR 4227 powder, the starting load is also 17.0 grains and the MV 1658 fps. The maximum load for that bullet is 19.5 grains for a MV of 1904 fps.

In its day, the .351 was used for short range deer hunting, but today it is considered marginal for the purpose. It is probably best restricted to use on animals of not more than about 50 pounds live weight, such as small predators. Visually, the .351 looks like a somewhat larger version of the familiar .30 Carbine round and, although the .351 is the more powerful cartridge, it is useful for similar purposes.

Chiefly because of the handy Winchester '07 carbine, the .351 cartridge enjoyed a rather long production life. The Model 07 was discontinued in 1957 and .351 ammunition was offered for several years after that. I can remember seeing it on Winchester's loading list when I was a teenager.

Note: A longer version of this article can be found on the Rifle Cartridge Page.