.55 inch Boys Ball & Practice
Ball Ammunition
The first Boys ball cartridge to be approved was the "Cartridge S.A. Ball .55 inch Mark I" introduced in LoC paragraph B.2245 dated April 1937. It was to Design DD/L/7818 and had a 930 grain flat based bullet with a cupro-nickel clad steel envelope with a lead/antimony core. The propellant charge was 186 grains of Cordite MDT 7-2. Muzzle velocity was 2,460 feeet per second.
The primer annulus was purple and included the numeral "I"
It was shown as obsolescent in March 1942.
The Ball Mark I was found to be inaccurate in worn barrels so a new ball cartridge with a thicker envelope was approved in January 1940 as the "Cartrdige S.A. Ball .55 inch Mark II" and shown in LoC Paragraph B.5834 dated March 1942. It was to Design DD/L/10506 and differed from the previous mark in having a mild steel core. In all other espects it was unchanged from the previous mark. It had a purple primer annulus and included the numeral "II".
It was shown as obsolescent in March 1942. .55 inch Boys Ball Mark IA higher velocity ball round was required to match the Armour-piercing W Mark II so the "Cartridge S.A. Ball .55 inch Mark III" was approved in February 1940 and shown in LoC Paragraph B.5834 dated March 1942. It was to Design DD/L/11816 (later DD/L/14009.3) and differed from previous marks by having a shorter 735 grain bullet with either a gilding metal or cupro-nickel clad steel envelope with a mild steel core in a lead/amtimony sleeve. the propellant charge was 212 grains of cordite MDT 7-2 and velocity was 2,900 feet per second.
Like previous marks it had a purple primer annulus and the headstamp included the numeral "III".
All .55 inch Boys ball ammunition seen was manufactured by Kynoch.
Packet label for Ball Mark III rounds. Note the use of Arabic "3" for the Mark number which indicates post 1944 production.
Practice Ammunition
Even the ball round of the new rifle was too powerful for many army ranges so it was necessary to develop training ammunition with less penetration and a reduced danger space behind the stop butt.
Experimental practice ammunition was made quite early and used cases originally intended for the .5 inch Stanchion gun as they are headstamped with "7246" the drawing number for that cartridge. They were also marked with a wide blue band above the belt on the case.
Trials were also directed to an alternative approach using a Boys cartridge necked down to .303 inch and a normal .303 inch ball bullet. Cases for these rounds were either simply headstamped "K 37" or with the addition of the .55 inch design number "7416". These were fired in a Boys with a special barrel, but tests proved that the recoil was only slight due to the weight of the weapon. Since one of the aims of a practice round was to get troops used to the recoil, the .55/.303 inch cartridge was rejected. Despite this, early editions of the Boys manual still included mention of the special .303 inch barrel. A few .55/.303 inch cases were made later in 1942 but these were connected with high velocity experiments. These cases were unheadstamped. .Shown on left is the .55/.303 inch Practice round and on the right the headstamp including the Design Number.
The "Cartridge S.A. Ball Practice .55 inch P Mark I" was approved in May 1937 and shown in LoC Paragraph B.2245 dated February 1939. It was to Design DD/L/7933 and utilised the standard case with the same lead cored bullat as the Ball Mark I with a charge of 103 grains of Cordite MDT 5-2. Velocity was 1,729 feet per second. The case had a blue band immediately in front of the belt with a purple primer annulus and the headstamp included the code "P I". The Practice Mark I was a stopgap and nothing more than the Ball Mark I with a reduced charge and hence lower velocity. The "Cartridge S.A. Ball Practice .55 inch P Mark II" was approved in January 1938 and shown in LoC Paragraph B.2245 dated February 1939. It was to Design DD/L/8763 (later DD/L/14009.2) differed in that it had a 425 grain aluminium cored bullet with a charge of 128 grains of Cordite MDT 5-2. Velocity was about 2,650 feet per second and accuracy was good to 500 yards. The case had a blue band immediately in front of the belt with a purple primer annulus and the headstamp included the code "P II".
The lead cored Practice P Mark I is shown on the left of each picture with the aluminium core P Mark II on the right.
Left: .55 inch Boys Practice Mark II
.55/.22 inch Adaptor
There was one other attempt to provide a practice round for the Boys rifle. This was a sub-calibre adaptor designed to fire .22 inch rimfire cartridges from an unmodified rifle on 25 yard indoor ranges. It consisted of a steel adaptor shaped to the normal Boys cartridge with a mock bullet bored through the length with a .22 inch chamber and a rifled barrel. The "primer" in the base was a rimfire striker.To use, the striker was pushed out using a rod, a .22 inch rimfire round inserted in the chamber and the striker replaced. The adaptor could then be loaded in the magazine like a normal round. When fired, the firing pin of the rifle struck the adaptor striker, forcing it forward and firing the .22 inch round. Accuracy from the short barrel of the adaptor is not known.The device was made both at RSAF Enfield in the UK and by Cooey in Canada but never received formal approval. .55/.22 Adaptor with striker on left.Next