.401 Winchester Self-Loading

.401 Winchester Self-Loading
.401 Winchester Self-Loading Rifle with .45-70 and .308 Win.JPG
.401 Winchester Self-Loading (Center) with .308 Win (left) and .45-70 (right).
Place of originUSA
Production history
DesignerWinchester Repeating Arms Company
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 thickness0.05 in (1.3 mm)
Case length1.50 in (38 mm)
Overall length2.005 in (50.9 mm)
Rifling twist1 in 14
Primer typeLarge rifle
Maximum pressure37,000 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

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

Description and performance[]

Illustration of a .401 Winchester Self-Loading rifle cartridge (1918).

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 1910 could provide substantial 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 Winchester Self-Loading cartridge.

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 cred 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 fitting, however, as in a carbine a cartridge will often product twice the muzzle energy over than when fired from a revolver barrel.[citation needed]


401 Winchester SL dimensions mm vertical.jpg

See also[]


  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.

External links[]