The .351 Winchester Self-Loading (.351 WSL, .351 SL)

By Chuck Hawks

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 and later .401 Self-Loading cartridges were 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. On the other hand, the Winchester Model 1907 rifle, actually a carbine with a 20" barrel, was lighter and trimmer than the clunky Remington semi-auto, which made Winchester's offering more popular.

The .351 WSL is based on a semi-rimmed, straight-walled case 1.380" long that uses small rifle primers. The rim diameter is .407" and the head diameter is .378". Cartridge overall length is 1.910". 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 (RN) 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 cast 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 hunting deer at short range, 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. A rather specialized application for which the .351 WSL was reportedly once popular was hunting the jungles of South America. This tended to be fast, very short range shooting where the energy of the .351's RN bullet remained high and the Model 07 carbine's indifferent accuracy was not a factor.

The .351 Self-Loading found considerable acceptance with US law enforcement and was particularly popular with prison guards. Winchester .351 carbines were purchased by the French military in limited numbers and used in both World Wars. It is a more powerful cartridge with better stopping power than the US .30 Carbine cartridge of WW II and Korean War fame and might have been a better choice than that round when the US Army went looking for a specialized carbine cartridge. The .30 Carbine even looks like a slightly smaller (rimless) version of the .351 WSL.

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.

Today, the .351 WSL is obsolete, as neither ammunition nor rifles are offered in the caliber. Still, it makes an interesting comparison with modern .357 Magnum carbines. The .357 Mag. fired from a lever action carbine has a much better reputation for accuracy than the .351 WSL ever did. On the other hand, the .351 WSL can drive the same weight bullet (180 grains) around 200-300 fps faster, so it definitely hits harder. If the .357 Magnum can be considered a short range deer cartridge--both the Winchester and Federal ammunition guides rate it suitable for CXP2 game--then the .351 WSL must also be.

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Copyright 2009, 2012 by Chuck Hawks. All rights reserved.