This article explains certain terms used for British ordnance during World War II.

BL

Bl stood for "Breech loading". The shell was loaded and then the propellant after in cloth bags. The breech mechanism was responsible for sealing the chamber. For British guns this was a Crossley pad with a interrupted thread screw block eg a Welin screw. A primer, not dissimilar in appearance to a blank rifle round was inserted into the breech for firing the gun. Breech may refer to: A breech birth The part of a firearm behind the barrel. ... The Welin breech block is a stepped, interrupted thread breech, invented by Axel Welin in 1889 or 1890. ...

ML

ML was "muzzle-loading".By World War II, there were no more muzzle-loaded guns in British use, so ML meant mortars, as the 'bomb' was dropped tail-first down the barrel from the muzzle. See mortar for more information. A muzzleloader is any firearm into which the bullet is loaded from the muzzle of the gun. ... Mushroom cloud from the nuclear explosion over Nagasaki rising 18 km (over 11 miles) into the air, August 9, 1945 after the Allied atomic bombings of Hiroshima and Nagasaki. ... Mortar has several meanings: A mortar is a military weapon into which is dropped a mortar shell, which is then fired in a high ballistic trajectory. ...

QF

QF came from "Quick-firing". In the 19th century, the introduction of field guns using a round formed from a metal (brass) cartridge containing the propellant and a shell in one unit gave higher firing rates. British guns by WW2 used a sliding breech which could be quickly operated - the cartridge was responsible for selaing the chamber just as in handguns. In some guns the round was complete, in others such as the QF 25 pounder gun-howitzer the shell was loaded separately to the cartridge into which the propellant was placed in its cloth bags. The primer for the round was in the cartridge base. Brass is an alloy of copper and zinc. ... Ordnance QF 25 pounder Type gun-howitzer Nationality UK Era World War II Target general use + anti-tank History Date of design 1930s Production period {{{prod_date}}} Number built Service duration 1930s - 1967 Operators {{{operators}}} War service {{{wars}}} Specifications Carriage Fixed trail Calibre 3. ...