List of British Ordnance Terms - Charge

Charge

Charge was a concept or category label rather than a specific item. It can be described as "the standard amount of propellant specified to carry out a particular purpose" :-

• Full Service Charge : the full amount of propellant intended for use in action at maximum range, for the usual shell. If a gun had e.g. a "heavy" and a "light" shell, there would be a separate Charge associated with the Heavy and Light shell.
• Reduced Service Charge : For practice or firing Star Shells (which were lighter than the normal shell).
• Proof charge : A charge giving 25% greater chamber pressure than the full service charge, intended only for the "proof" or testing of a gun.
• Blank Charge : Intending for firing without a projectile, usually a reduced charge.
• Battering Charge : a specially large charge for use with "Palliser" projectiles, which were an early British armour-piercing projectile of the mid-to-late 19th century.

For practical purposes, specific Cartridges were specified for use to obtain the required Charge. A gunner dealt with cartridges and would know that he could load (e.g.) Cartridge X or Y for a full service charge for his gun, and Cartridge Z to fire a Star shell. Cartridges were sometimes made up of fractions of charges e.g. a 6 inch gun cartridge may be made up of 2 x 1/2 Charges or 1 x 2/5 and 1 x 3/5 Charge laced together. A gun normally fired all rounds using the full charge, and varied the range by elevating or depressing the barrel.

A howitzer gunner's job was more complicated because the range table would specify different "charges", or fractions of the full service charge, for different ranges and angles of shell descent. The standard cartridge for his gun which as a whole made up the full service charge, would consist of a central "mushroom" Cordite core and several smaller Cordite rings in bags stacked around the core like doughnuts, all tied together. It was designed so that 1 or more rings could be quickly removed and discarded before loading, hence providing progressively smaller charges. E.g. if the gunner on a QF 4.5 inch Howitzer was ordered to load Charge 4 he would know he had to remove the top ring from the cartridge, leaving 4 rings; for Charge 3 he would remove 2 rings. Discarded rings were burned after the action. This was the standard procedure for howitzers up to and including World War II.

In World War II a different system was introduced for varying charges for the QF 25 pounder gun-howitzer, which used separate-loading QF ammunition. A separate 2.7 lb "super charge" cartridge was available for firing the 20-pound high-velocity anti-tank AP shot, and an additional 4.5oz "super charge increment" could be added to that for even higher velocity. The cartridge for firing the standard 25-pound shell came ready-loaded with a red bag at the bottom containing the basic charge (Charge 1), together with white and blue bags laid lengthwise, as in a conventional gun charge, to make up the full service charge (Charge 3). The blue and white bags could be removed to provide progressively reduced charges (Charge 2 and Charge 1). From 1944 1 or 2 4oz "intermediate charge increments" could be added to the standard charge (replacing the blue bag) for high-angle fire and to provide greater control over angle of shell descent.

For small arms or fixed QF ammunition, where the charge could not be varied by the gunner, the term Charge was used to identify the Cordite propellant within the cartridge case, and the round as a whole was referred to as Full or Reduced charge. E.g. an 18 pounder Star round consisted of a cartridge case containing a Reduced charge, and an attached Star shell.