The 3.45 inch RCL was an 88mm British recoilless weapon, designed by Sir Dennis Burney during the Second World War. Delayed by problems due to breech wear because of gas erosion upon firing, it did not see action, as was hoped, in the Far East, particularly Burma. However it did lead to the post war Mobat and Wombat recoilless rifles.

The 3.45 inch RCL was built by the Broadway Trust Company, a company formed by Sir Dennis himself. Sir Dennis was privy to the design of the 20mm m/42, a recoilless rifle designed by the Swedish Bofors Carl Gustaf company during World War 2, but it had little bearing on his work as the Carl Gustav was a large bore rifle design intended to remove the recoil experienced with anti-tank rifles such as the Boys anti-tank rifle or similar large calibre bolt-action rifles which required large cartridges to deliver high velocity rounds. The usefulness of anti-tank rifles was lost as tanks were built with much thicker armour during the war. Although Burney's designs did not have high muzzle velocities, this was compensated for by the use of a shell which relied on a HESH explosive instead of speed and weight to penetrate the armour.

This was a weapon that could be fired from the shoulder, giving unrestricted traverse or elevation within the limits of the human frame, or mounted on a simple tripod. A portion of the propelling charge bled through holes in the cartridge wall and into a space around the breech and then backwards through four venturis. This counter blast backwards cancelled out the recoil.

Ordnance, RCL, 3.45in Mk 1^[1]