100mm Field Gun M1944 (BS-3)

Beginning in 1932 with the 45mm M1932 and the 45mm M1937, the Soviet Union followed the same path of caliber escalation. Adopted in 1942, the 45mm M42 was essentially a larger-bore copy of the German 37mm antitank gun. The M42 was quickly superseded in 1943 by the more potent caliber 57mm ZIS-2. The excellent ZIS-2 was, in turn, superseded in 1944 by the semiautomatic 100mm Field Gun M1944 (BS-3). Originally based on a naval design and mounted on a dual-tire split trail carriage, the M1944 fired a 35-pound high-explosive shell to a maximum range of 22,966 yards and an antitank projectile to an effective range of 1,093 yards. With a crew of six, the M1944 was capable of firing up to 10 rounds per minute. Although the 100mm T-12 eventually replaced the M1944 in Soviet service, many remain in use around the world.

The BS-3 was based on a B-34 naval gun. The development team was led by V. G. Grabin.

The gun was employed by light artillery brigades of tank armies (20 pieces along with 48 ZiS-3) and by corps artillery.

In the Second World War the BS-3 was successfully used as a powerful anti-tank gun. It was capable of defeating any contemporary tank at long range. The gun was also used as a field gun. Though in this role it was less powerful than the 122 mm A-19, as it fired a smaller round, the BS-3 was more mobile and had a higher rate of fire.

The BS-3 entered production in 1944, and then only 341 were built that year: 66 at Zavod Number 7, 275 at Zavod Number 232. In 1945, including the last half of the year when the war was effectively over, another 1140 were built: 720 at Zavod 7, 420 at Zavod 232. 

The first artillery units with the 100mm gun were not actually antitank units. According to a General Staff order GOKO-6270ss dated 29 July 1944, 5 Corps Artillery Brigades were to be formed to shtat 8/613 and 8/917 with 2 regiments, one of 20 152mm howitzers and one with 20 100mm BS-3 cannon. (Most of the Corps Brigades so formed never went to the front, but instead were reformed as Howitzer Brigades in late 1944, probably so that the 100mm cannon could be diverted to antitank units) 

Initially, one battery in each antitank regiment was going to be equipped with 100mm guns, but this order was rescinded in December 1944, when a new NKO Order, number 0050 dated 25 December 1944, ordered that one regiment in each of 12 antitank artillery brigades was to be re-equipped with 100mm guns (16 per regiment) by 15 January 1945. When the 9th Guards Army was formed in early 1945, it received a 13th antitank brigade with a 100mm gun regiment, and also three new Corps Artillery Brigades (61st, 62nd, 63rd Guards) each equipped with a regiment of 100mm guns.

Therefore, by the end of the war in Europe, the Red Army had 13 antitank brigades and 3 Corps Artillery Brigades each with one regiment of 100mm guns, for a total of 268 BS-3 100mm cannon in service with the units. 

100mm Field Gun M1944 (BS-3)

Adoption date: 1944

Caliber: 100mm

Weight: 7,617 pounds

Breech : semiautomatic vertical sliding block

Barrel length: 239 inches

Elevation: 45°

Traversal: 58°

Projectile weight: 35 pounds

Muzzle velocity: 2,953 fps

Maximum range: 22,966 yards