Well, there are some side-by-side designs, namely the French systeme called Ideal, that cock by the motion of the opening lever. I think I remember reading somewhere that the same company (? - Manufrance - ?) made or tried to make an o|u on the same principle, but I am possibly wrong here.

However, the Izhmech (better known abroad as Baikal) company used to make a .22/.410 combination o/u for Remington, marketed as Remington Spr 94, and this gun cocks on the motion of the openiing lever. smile