.55 inch Boys

History

Late in WWI Britain had started to develop an anti-tank rifle designed by Mr.Godsal of Webley and Scott Ltd., who manufactured the pilot models. These were chambered for the newly developed .600/.500 inch cartridge which was under consideration for Air Service. (discussed here). Development had not progressed far when the war ended and in the immediate post -war period there was neither the funds nor the interest for further work.


The prototype Godsal anti-tank rifle, 1918

The Stanchion Rifle

Some funds had become available by the 1930s and the genesis of the .55 inch Boys rifle was a request to the Small Arms Committee in late 1934 to investigate the development of a shoulder fired anti-tank rifle. This led to a General Staff requirement issued in January 1935 for a rifle weighing no more than 35 lbs with penetration of 25mm of armour at normal attack at 200 yards and 14mm penetration at normal attack at 500 yards. From the beginning it was intended that the investigation should include use of a coned barrel on the Gerlich system as well as conventional ammunition.

As part of the investigation a captured German 13mm T-Gewehr was used in a modified mounting to reduce recoil. The SAC reloaded German cases with British projectiles and also purchased 250 rounds of new 13mm A.P. ammunition from abroad. It is not known where these came from but at that time the ammunition was being made in Belgium, Sweden and Switzerland.

The prototype rifle was ready by mid 1935 and was chambered for a .5 inch cartrdidge based on the 13.2mm Hotchkiss case1. Unlike the Hotchkiss it was a belted design and the necking was more acute. Already at this stage the weapon was being refered to as the "Stanchion" rifle, a code name given for security purposes.

AP bullets of both 700 grains and 800 grains weight were tested but the shooting of the 700 grain bullet was described as "indifferent" and the 800 grain bullet became the norm. With this the G.S. penetration requirement was met but it was felt that with the advances in armour the question of calibre should be reconsidered. At the same time, the rifle was renamed the Boys, in tribute to Captain Boys of the Design Department who had recently died.

The .5 inch Stanchion round was made in Armour-piercing, Drill, Dummy and possibly Tracer loadings by Kynoch.

Illustrated are Kynoch made .5 inch Stanchion Drill and Armour-piercing cartridges.

There was also an earlier 1934 case design that had a wider diameter ahead of the belt but it is unlikely that many were actually made.

Following further trials an increase in calibre was made to .55 inch. The cartridge case was unchanged apart from the increase in neck diameter.


1 Minutes of the Small Arms Conference held at the Ballistics Branch, Woolwich, 10 March 1936.