.401 Winchester Self-Loading

The .401 Winchester Self-Loading (also called .401SL or .401WSL) is an American rifle cartridge.

.401 Winchester Self-Loading
.401 Winchester Self-Loading (Center) with .308 Win (left) and .45-70 (right).
Type	Rifle
Place of origin	USA
Production history
Designer	Winchester Repeating Arms Company
Specifications
Bullet diameter	.4065 in (10.33 mm)
Neck diameter	.428 in (10.9 mm)
Base diameter	.429 in (10.9 mm)
Rim diameter	.457 in (11.6 mm)
Rim thickness	0.05 in (1.3 mm)
Case length	1.50 in (38 mm)
Overall length	2.005 in (50.9 mm)
Rifling twist	1 in 14
Primer type	Large rifle
Maximum pressure	37,000 to 39,000 PSI
Ballistic performance
Bullet mass/type Velocity Energy 200 gr (13 g) 2,141 ft/s (653 m/s) 2,037 ft⋅lbf (2,762 J) 250 gr (16 g) 1,875 ft/s (572 m/s) 1,952 ft⋅lbf (2,647 J)
Test barrel length: 20 Source(s): Whelen, Townsend. The American Rifle. Century Co. 1918 p. 266

Winchester introduced the .401SL in the Winchester '10 self-loading rifle as a supplement to the Winchester '07 and the .351SL in their offering of hi-power, self-loading rifles. The only chambering available in the Winchester Model 1910, the .401SL was used by France, Russia, and American company security forces in the First World War.[1]

The .401SL proved powerful enough for both deer and other large game at ranges under 150 yards.[2] Both 200gr and 250gr bullet weights were offered by Winchester and other ammunition manufacturers as factory loadings. With extra available detachable magazines holding 4-rounds each, the Model '10, could provide much firepower for the big-game hunter. This feature helped promote the use of the .401SL on dangerous game such as moose and grizzly bear in spite of the lack of controlled expansion bullet designs, which doubtlessly would have improved game-taking performance and the subsequent reputation of the .401SL cartridge.[3]

The .401 SL is of similar size to the later .41 Remington Magnum; but the longer self-loading rifle cartridge produced a muzzle energy of 2,000 foot-pounds force (2,700 J) with a 200-grain (13 g) bullet,[4] while the magnum revolver is credited with a muzzle energy of 790 foot-pounds force (1,070 J) with a 210-grain (14 g) bullet.[5] The .41 Rem magnum revolver comparison is not entirely relevant, however, since in a carbine the same cartridge generally at least doubles its energy over the much shorter barreled version.

See also

• List of cartridges by caliber
• List of rifle cartridges
• Table of handgun and rifle cartridges
• 10 mm caliber

References

1. Houze, Herbert G. (2003). Winchester's First Self-Loading Rifles. 'American Rifleman' Vol 151(5) p.84.
2. Whelen, Townsend. The American Rifle. Century Co., 1918. p.274
3. Stebbins, Henry M. Rifles, A Modern Encyclopedia. Stackpole Co., 1958. p.274
4. Sharpe, Philip B. (1953). Complete Guide to Handloading (3rd ed.). New York: Funk & Wagnalls. pp. 425&436–437.
5. Ramage, Ken (2000). Gun Digest 2001 (55th ed.). Iola, Wisconsin: Krause Publications. p. 208. ISBN 0-87341-924-3.