The firing pins would have to be bushed and replaced if chambering to anything of more pressure than a rimfire. I would stay away from anything over about 25,000CUP or PSI, which is RF pressure, btw. Of course, the breech thrust from the rimfires is much less due to diameter. European .22 Hornet ammo would be OK, I guess as it's loaded to lower pressure than US ammo. Still, it would need a small firing pin. In loading Hornet ammo in a rifle with a large pin, I was restricted to holding velocities under 2,300fps or primer flow would cause piercing due to the large pin and pin-hole.
: Even a .30/30 needs a standard small pin, not larger than 1/16" in diameter, due to it's 34,000CUP breech pressures.
: I would go the rimfire, myself, and a .22LR or .22WMR would suffice. This rifle, with iron sights would not do justice with the .17HMR, although the .17Mach2 would be a candidate.
: You could conceivably sleeve and chamber of a black powder ctg. such as the .32/40 or .38/55 and use black powder equivalent loads with the large pins. As long as pressure is held to under 30,000CUP/CIP or about 26,000PSI, this would be OK.