Diagram of British QF 12 pounder Common Lyddite shell Mk IV (3 inch) with internal night tracer, 1914. For both Naval and Land use.
Mark IV was the latest 12 pounder explosive shell in 1915. It had increased thickness in the base to take the internal night tracer, hence less space was available for explosive than for previous Mks of the shell.
The tracer was for anti-aircraft use in the 12 pounder 12 cwt gun.
Takes G.S. 1 inch fuze. The drawing shows the fuze hole with a plug screwed into it, which was the usual safety practice of storage to keep the fuze hole unexposed and clean until required for firing. The plug was then removed and the fuze was screwed in.
Weight filled and fuzed : 12 lb 8 oz.
Length : 8.92 inches.
Diameter : 2.98 inches (shell); 3.095 inches (driving band).
Filling : 12 oz 3 drams Lyddite, 5 drams TNT exploder. Total 12 1/2 oz.
For use in the following guns :-

• QF 12 pounder 8 cwt (navy landing gun)
• QF 12 pounder 12 cwt naval gun
• QF 12 pounder 12 cwt AA gun
• QF 12 pounder 18 cwt naval gun
• QF 14 pounder naval gun