Royal Ordnance 165mm L9 Demolition Gun, initially called Ordnance BL 6.5" Mk I, is a British short-barrelled gun used for combat engineering, particularly the demolition of defences.
The gun is capable of firing a High Explosive Squash Head (HESH) demolition projectile distances up to . The HESH shell contains of C-4 explosive.http://britains-smallwars.com/gulf/gulfweapons.html
The L9 gun was mounted on Royal Engineers AVRE versions of the Churchill and Centurion tanks after the Second World War.
The gun's primary purpose is the clearing of obstacles such as walls, fences, roadblocks or bunkers, and the destruction of buildings.
Variants
L9A1: improved version M135: American version, used on M728 Combat Engineer Vehicle, variant of the M60 tank.
Citations
General and cited references US Army Field Manual FM 5-103 Survivability, Appendix A, Headquarters, Department of the Army, Washington, D.C., 10 June 1985 Hunnicutt, R. P. Patton: A History of the American Main Battle Tank. 1984; Presidio Press. .