So even though the Miroku / Winchester model 1873 will be made of modern steel it is a relatively weak designed action !
Toggle link actions are not notoriously strong, but they are not weak either. Read up on the tests Winchester did when they designed the 1876 rifle. They actually tried to blow one up. I can't remember the details, but the only way they finally succeeded in damaging the rifle was to lodge several bullets in the bore, then fire a full case of 3F or 4F behind them, and even then it just blew the side plates off. So with modern steel and pistol cartridges it should be good to go.