Joey,
No gun made in 1910 was designed for modern SAAMI-spec loads. You aren't going to blow the thing up (Prussian Dalys are strong guns), but by shooting modern loads in the gun of this vintage you would subjecting the gun to stresses beyond which it was designed which is never a good idea. It is not good for the gun and there is no reason to do it.
The good news is that appropriate pressure rounds are easily obtained from RST, Gamebore, Eley, and several others. While these will sell at a small premium as compared to the stcok down at the local Gander Mountain, this is not a big deal. The extra $25 for a flat of shells doesn't mean much when you have dropped several grand on a beautiful vintage piece. Theses loads will also kill any bird that has ever flown or any clay ever thrown.
Good luck,
Ken
Last edited by Ken Georgi; 07/20/10 06:09 PM.