In the last post, we studied that the Mauser T-Gewehr was invented by the Germans because they didn't have any tanks of their own during World War I and had to come up with some solution to counter British and French tanks. Although tank armor had become thick enough to resist the Mauser by the end of World War I, the idea of an anti-tank rifle did not go away.
In 1934, the British decided to design a weapon that could penetrate light armor. The project was originally called Stanchion and was given to the Royal Small Arms Factory of Enfield, Middlesex, England to design. The chief designer of this project was a Captain H.C. Boys.
Captain Boys intended the rifle to be a bolt-action large bore rifle, capable of penetrating light armor, but light enough to be carried by a single person. He looked at the existing rifle cartridges of the day. The 30-06 and the .303 cartridges were found to be too weak (even the armor-piercing variants). The US made Browning .50 BMG cartridge was found to have some potential, because it could penetrate 3/4" armor at 100 yards, but they wanted something a bit more powerful than the .50 caliber cartridge. Therefore, they started with a Browning .50 caliber cartridge case, widened the case's neck to accept a .55 caliber steel-core bullet and added a belt around the cartridge base for proper headspacing (the idea of adding a belt on the base of a magnum cartridge was a British invention by Holland & Holland in 1910 for their larger hunting rifles firing the powerful .375 H&H magnum cartridges). This new cartridge weighed 946 grains (64 gm.) and had a velocity of 2495 feet/sec, delivering 17726 ft-lbf (24033 joules) of energy. By comparison, the .30-06 cartridge (all variants) delivers somewhere between 2800 to 3000 ft-lbf of energy. The job of manufacturing the new .55 caliber cartridge was given to Kynoch Ltd., a well known manufacturer of cartridges in England.
With the cartridge designed, the next goal was to design a rifle around this cartridge. It was simply a bolt-action design with a 5-round magazine, weighed about 35 lbs. (16 kg.) and was about 5 feet 2 inches (1.575 meters) long. The magazine was top-mounted and therefore, the sights were offset to the left to accommodate this. Tragically, the designer of this rifle, Captain Boys, died a few weeks before the rifle went into production in November 1937. Hence, the rifle was renamed as the Boys Anti-tank Rifle in his honor.
The Boys Anti-tank Rifle Mark I. Click on image to enlarge. Public Domain Image.
The rifle was manufactured in three variants. The Mark I variant (as shown in the image above) was the original design manufactured by the Royal Small Arms Factory in Enfield. Notice the round muzzle brake and the T-shaped bipod The Mark I* was given to the Canadian company, John Inglis & Co. to manufacture and this variant had a V-shaped bipod and flat muzzle brake. The Mark II Airborne variant was designed to be carried by paratroopers and had a shorter muzzle.
When the Boys rifle was delivered, it was not effective against German panzers since the very beginning of World War II. While the bullet fired by this rifle could penetrate through mild steel plate of 23.2 mm. thickness (almost 1 inch thick) at about 90 meters (100 yards) range, the frontal armor of the German tanks was thicker and harder than this and therefore the rifle didn't fare very well against them. However, they proved to be more effective against armored cars and Soviet and Japanese light tanks. The Finns used them against Soviet tanks in 1940. The original steel-cored bullet was later replaced by a tungsten-core bullet (the .55 Mark II cartridge) in an attempt to improve its effectiveness. Despite the cushioned butt pad on the stock, the recoil from this weapon was terrific and often ended up bruising the operator's shoulder, which made soldiers very reluctant to fire it unless it was mounted to a support. This weapon did find some success with the British commandos of World War II (the Desert Rats), who mounted it to the top of their trucks and Bren carriers, when they went on raids in the desert.
Since the rifle had such a heavy recoil, an adapter kit was designed to be used by this rifle for training purposes.
What the adapter kit did was allow the user to mount a smaller .22 caliber rifle to the side of the Boys rifle and fire that via the trigger of the Boys rifle. This allowed for users to learn basic sighting techniques, without having them to bear the force of firing the Boys rifle during training sessions.
The Walt Disney Company was also commissioned to produce a training video for this gun during World War II:
Yes, that is a Disney cartoon animation at the beginning of the first video.
While the Boys rifle was largely ineffective in its original role of stopping German tanks, it was more effective against lighter skinned vehicles, early Soviet and Japanese tanks and armored vehicles. US Marines used it against Japanese bunkers as well. By the end of World War II, this rifle was seen as obsolete and was replaced by bazooka type anti-tank weapons. However, they were still used in the Korean war and in the Philippines until 1960 or so. One was even used in the 1960s by the IRA to disable a British Navy Patrol Boat HMS Brave Borderer by shooting out one of its turbine engines through the hull of the boat.