There was a 577-450 incendiary round produced. The case was drawn brass and the bullet was a large spitzer type bullet with incendiary filling and a base closed by a steel washer with central vent. The incendiary compound, in this case a tracer composition, was ignited by the discharge of the cartridge. The round was known originally as 'Cartridge SA Incendiary .45 inch Mark I' when introduced in 1914. Later, in 1916 it was renamed, 'Cartridge SA Tracer Martini Henry Rifle and Machine Gun Mark I.' The round was replaced by the 303 BIK Mark VII.K incendiary eveloped by wing commander Brock, RNVR.
Their shoulders held the sky suspended;
They stood and Earth's foundations stay;
What God abandoned these defended;
And saved the sum of things for pay.