The M1903-A4 was a specifically designed sniper rifle that came as a result of early U.S. combat involvement in the Pacific. There was a high demand, that could not be filled, for telescopic (sniper) rifles. The Infantry Board and the Ordanance Department conducted an evaluation and recommended that the Weaver 2.5x 330C hunting telescope be adopted for use on M1903 and M1903-A1 rifles. The rifle was officially adopted on 14 Jan 1943 as the M1903-A4 (sniper).
The M1903-A4 was an accurate rifle with an effective range of about 600 yards (550m), with the main limit on long range accuracy coming from its very low power scope (2.5x). From its adoption in 1943 until the end of the war, the M1903-A4 was used extensively in every theater of operation by both the US Army and the USMC. The rifle was again used in the Korean conflict, and even in the early stages of the Vietnam conflict when sniper rifles were in severe shortage. The M1903A4 is a legendary classic sniper rifle. It served with distinction in WWII, Korea, and even Vietnam.
Unlike the US Army, the USMC had a standard issue sniper rifle at the start of hostilities in WWII, it was a M1903/Lyman 5A (5x), which was adopted (with the Winchester A5 Telescope) during WWI. After there was a push to standardize sniper equipment, the Marine Corps Equipment Board did an extensive study of optics under field conditions and recommended a scope of about 8x, with an objective lens of about one and half inches, a medium fine crosshair reticle, and double micrometer quarter minute click mounts. They specifically cited a 8x target scope made by John Unertl as being the best they found. They also recommended the scope be mounted on a Winchester M70 target rifle, but the USMC decided on the M1903 based on favorable accuracy comparisons between specially selected M1903’s and the M70. So the M1903-A1 mounted with the Unertl 8x became the “sniping standard” in the USMC.
The M1903-A1/Unertl was tested and at 600 yards and with M72 Match ammo would group 3.5 inches (.58 MOA, wow!!!) but match ammo was about impossible to come by during the war, so most snipers had to settle with M2 Ball ammo, which was till respectable with groups coming in at 7.5″ at 600 yards (1.25 MOA). The M1903-A1/Unertl was used by the USMC through out WWII, along with the M1903-A4. The -A1/Unertl also saw use during the Korean war, with USMC snipers registering a number of kills out to 1000 yards. Like the M1903-A4 the M1903-A1/Unertl was a lethal system in the hands of a properly trained sniper during WWII and Korea.
Thanks to a loyal SC follower for the images.