A quick look at .30-40 Krag, or .30 U.S. Army, America’s first small-bore military cartridge.
The .30 U.S. Army, or .30-40 Krag—the first United States small-bore military cartridge—was adopted in 1892.
The Winchester high-wall single-shot was the first commercial rifle in the United States produced for a small-bore smokeless-powder cartridge. This happened when the .30-40 Krag was added to the available chamberings in 1893. The Remington-Lee bolt action, Remington rolling block, and Winchester Model 95 lever action and high-wall single-shot were the first commercial sporting rifles to offer this chambering. No commercial rifles used the cartridge from 1936 to 1973. From 1973 until 1977, the Ruger No. 3 single-shot was chambered for the .30-40 Krag, thus stimulating a renewed interest in the cartridge.
The .30-40 Krag—.30-caliber/40 grains of the original smokeless-powder load—has retained its popularity, primarily because large numbers of fine sporting conversions of the Krag military rifles and carbines chambered for it are still in use. Although not quite as powerful as either the .30-06 or the .308 Winchester, the .30-40 is well suited for use on North American big game. The Krag earned its reputation with the 220-grain loading, but it can be loaded to great advantage with lighter bullets for smaller species.
Interestingly, most authorities consider the 1895 Winchester chambering to be safe with loads at a somewhat higher pressure than the Krag rifle. However, both actions have limitations, and one should be particularly circumspect in this regard.
Bountiful loading data can be found in current manuals. The .30-40 is the basis of an entire genre of powerful Ackley Improved chamberings particularly suited to strong single-shot rifles. The 180-grain bullet is the dominant offering, but 150-, 165- and 220-grain loads can be found online.
.30-40 Krag Loading Data and Factory Ballistics
| BULLET | POWDER | GRAINS | VELOCITY | ENERGY | SOURCE |
| 100 SP | H322 | 45 | 3,000 | 1,999 | Speer |
| 110 SP | IMR4320 | 47 | 2,700 | 1,781 | Sierra, Speer |
| 125 SP | IMR4895 | 44.5 | 2,600 | 1,877 | Sierra |
| 130 SP | IMR4064 | 44.5 | 2,900 | 2,428 | Hornady, Speer |
| 150 SP | IMR4895 | 40 | 2,400 | 1,919 | Nosler, Sierra |
| 165 SP | IMR4350 | 47 | 2,500 | 2,290 | Hornady, Nosler, Sierra |
| 180 SP | IMR4350 | 46 | 2,450 | 2,400 | Nosler, Sierra, Speer |
| 180 SP | IMR4895 | 39 | 2,200 | 1,935 | Sierra |
| 200 SP | IMR3031 | 34 | 2,100 | 1,959 | Nosler, Speer, Sierra |
| 220 SP | IMR4350 | 42 | 2,100 | 2,155 | Hornady, Speer, Nosler |
| 180 JSP | FL | — | 2,430 | 2,360 | Remington 28345 |
| 220 RNSP | FL | — | 2,046 | 2,044 | Buffalo Arms AMO3040KRAG2 |
Editor’s Note: This article is an excerpt of Gun Digest’s Cartridge’s Of The World.
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