These guns were designed primarily as anti-tank weapons. One was 3.45in in calibre and could be fired off a man's shoulder or from a light tripod. The other was 3.7in in calibre, and carried on a light two-wheeled mounting. The 'Ordnance RCL 3.45in Mk 1' weighed 751b (34kg), was 68.5in (1.74m) long, and fired an 11lb (5kg) wallbuster shell to 1,000 yards. No penetration figures were ever made public, but it is fairly certain that it could knock a 10lb (4.5kg) slab off the back of 6in (150mm) of armour plate at any range it could hit. The 3.45in recoilless gun, because of its calibre it came to be called 'the 25-pounder shoulder gun'. It took a reasonably strong man to carry it, let alone fire it off the shoulder, but it could be done. The 3.7 was a larger weapon, weighing 222lb (100kg); it was 112in (2.84m) long and fired a 22.2lb (10kg) wallbuster to 2,000 yards, it is estimated that this could have dealt successfully with armour up to 10in (254mm) thick. The 3.7in recoilless gun showed a great deal of promise as an anti-lank weapon, hut it came too late. Both weapons were overtaken by events, with the war ending before they could be put into production. Both were produced in limited numbers in 1945-46 and were used for extensive user trials, but they were then withdrawn and scrapped. After this time, development of recoilless guns took a different direction under different management. Breech end of the 3.7in RCL gun,showing the six jets surrounding the breech.