Right, I understand what you mean now!
The pictures of the rifle mechanism and the small calibre recoilless rounds are of the 7mm Broadway Trust Company weapon, developed by Sir Dennis Burney in the UK at the end of WW2 and in the immediate post war period. The drawing is from the patent.
The rifle came to nothing but his designs in larger artillery calibres (3.45 inch etc.) led to the British WOMBAT and MOBAT series of RCL anti-tank weapons.
Regards
TonyE