M1917 Enfield - Design Details

Design Details

Both P14 and M1917 rifles are noted for several design features. The rifle was designed with a rear receiver aperture sight, protected by sturdy "ears," a design that proved to be faster and more accurate than the typical mid-barrel sight offered by Mauser, Enfield or the Buffington battle sight of the 1903 Springfield. Future American rifles, such as the 1903-A3 Springfield, M1 and M1 Carbine would all use such receiver sights. The M1917 sight was situated on an elongated receiver bridge, which added weight to the action, as well as lengthening the bolt. The M1917 action weighs 58 oz (1,644 g) versus 45 oz (1,276 g) for the 1903 Springfield.

The rifle maintains the British cock-on-closing feature, in which the bolt's mainspring is loaded and the rifle cocked as part of the return stroke of the bolt, which aided rapid fire, especially as the action heated up. Most bolt action designs after the Mauser 98 cocked as part of the opening stroke. The rifle has a characteristic "belly" due to a deeper magazine, allowing the rifle to hold six rounds of the US .30-06 cartridge in the magazine, and one in the chamber. In a manufacturing change from the Mauser 98 and the derivative Springfield, the bolt is not equipped with a third 'safety' lug. Instead, as on the earlier Model 1895 (Chilean) Mauser, the bolt handle recesses into a notch in the receiver, which serves as a emergency locking lug in the event of failure of the frontal locking lugs. This change saved machine time needed on the rifle bolt, cutting costs and improving production rates, and this alteration has since been adopted by many commercial bolt action rifle designs for the same reasons. The location of the safety on the right rear of the receiver has also been copied by most sporting bolt action rifles since, as it falls easily under the firer's thumb. One notable design flaw was the leaf spring that powered the ejector, which could break off and render the ejector inoperable. A combat expedient repair method was to slip a bit of rubber under the bolt stop spring. A redesigned ejector, incorporating a small coil spring in place of the fragile leaf spring, was developed and can be fit to the M1917 to remedy this issue.

The M1917 was well-suited to the powerful, rimless .30-06 round which was closer in overall length and ballistics to the original high-velocity round for which the rifle had been designed than the rimmed, less powerful .303 round of the P14. The M1917's barrel retained the 5-groove left hand twist Enfield-type rifling of the P14, in contrast to the 4-groove right hand twist rifling of the M1903 Springfield and other US designed arms.The M1917 had a long 26-inch heavyweight barrel compared to the lighter 24-inch barrel of the M1903 Springfield. With the longer sighting plane, the M1917 proved generally more accurate at long distances than the M1903, at the expense of greater weight. The M1917 weighed 9 lb. 3 oz. (4.17 kg) empty, and a rifle with sling, oiler, and fixed bayonet weighed over 11 pounds. The M1917's long barrel and issued 16.5-inch blade bayonet proved too lengthy and cumbersome for trench fighting, while its weight and overall length made the rifle difficult to use for some smaller-statured soldiers.

Many M1917 rifles were refurbished during World War II with newly manufactured High Standard and Johnson Automatics barrels which had 6-groove and 2-groove rifling respectively.