The British Army adopted its first anti-tank rifle, the Boys, in 1937 firing a .55 steel round designed to pierce the armour of tanks of the date and injure or kill their occupants by bouncing around inside the vehicle. The manual explains:
Its bullet will penetrate their armour up to about 500 yards range and inflict casualties on the crew, although it may not seriously damage the vehicle itself.
The Boys was a heavy bolt action rifle and the round it used was equally large, being based on the .50 calibre Browning cartridge, but necked up to take a .55 bullet. A belt was added to the base of the cartridge to stop it being accidently fed into a .50 calibre machine gun:The round was developed by Captain H Boys at the Royal Small Arms Factory, Enfield and used a hardened steel core bullet with a lead sleeve:The initial poor performance of the round led to a MkII round with greater penetration, at the optimum angle the bullet was able to pierce .91 inches (23.2mm) of armor at 100 yards, .82 inches (20.9mm) at 300 yards and .74 inches (18.8mm) at 500 yards. The head-stamp of this round indicates it was manufactured in 1941 by Kynoch and is a Mk II round:The ammunition was issued in five round stripper clips, the weapons training manual explaining how much ammunition was issued:
Ammunition– The ammunition will be carried as follows:-
- In the truck or corresponding vehicle- 200 rounds for each anti-tank rifle. Of these, 160 rounds are in 16 bandoliers, each holding 2 clips of five rounds, and 40 rounds in eight magazines.
- In reserve, 40 rounds for each anti-tank rifle.
Due to the power of these rounds, no normal rifle range was large enough to accommodate them, so lower powered .22 training rounds were used to allow troops to train. It was expected that once trained a soldier could fire nine rounds a minute, however the recoil of the weapon was excruciating and the performance of the round mediocre at best compared to contemporary anti-tank rifles of the other powers. With ever increasing thicknesses of armour the Boys was obsolete before it entered service, but had to soldier on until replaced by the PIAT in 1943. It is fair to say that on withdrawal the rifle and its round were not mourned by those who had to use it.