Let me say this one more time, you will not be able load a 38/55 into the chamber on a small action Cadet or 1215. The straight walled cartridge is too long and fat.

Any cartridge loaded into a martini must turn an arc to be loaded. A 38/55 rim will bind at the rear of the breech block and on the bullet or case wall at the top of the chamber.

Large long cartridges must be tapered to fit-smaller in front to make the arc.