Projectile 155 mm: WP/Smoke, M110, M110A1 and

Phosphorus (WP), although other fillings have been used. A centrally located burster charge extends the length of the shell interior. On the 155 mm Smoke WP M110 the burster charge is the M6 containing 186 g of Tetrytol. On the 155 mm Smoke WP M110A1 and M110A2 the burster charge is the M54A1 containing 208 g of Composition B5. On the M110A1 the end of the burster tube is sealed with a plastic plug; on the M110A2 the sealing plug is aluminium. The 155 mm Smoke WP M110 family is normally fitted with a nose-mounted point detonation fuze. On impact the fuze ignites the internal burster charge which then ruptures the shell casing to release the WP filling. As it contacts the air the WP ignites to produce thick clouds of white smoke. The M2 flash reducer pad is used with this charge. The M3 and M4 series of charges are fired using the MK2A4 or M82 primer. The M2 flash reducer pad used with these charges is a 101.6 mm square red cotton cloth bag containing black powder and potassium sulphate or potassium nitrate. The Propelling Charge M119 is a single white bag charge in a laced jacket fired as Charge 8. It has an igniter bag sewn onto the base and a flash reducer pad is located on the front of the bag; the forward end also contains lead foil as a decoppering agent. The M119 contains approximately 8.62 kg of cool-burning M6 propellant with a central igniter consisting of a moulded nitrocellulose tube containing benite strands. The Propelling Charge M119A1 has some design improvements over the M119 including a modified ring-shaped flash reducer. The Propelling Charge M119A2 uses a red charge bag and does not have a laced jacket. It is provided with an igniter protector cap and tie strap which must be removed before firing; the circular red cloth igniter pad weighs 113 g.