Good choice, Bonanza.

I have heard of pressure excursions with heavy loads of T-7 in large bores, but others say they use up to 175gr. ina Pedersoli 12 bore - I certainly wouldn't. Hodgdon says to reduce BP loads by 15% to 20% IIRC. Since it is probably a percholate powder, it's fouling by itself will be corrosive - just like Pyrodex - sounds like it with brass.

I tried T-7 in my 14 bore rifle and it was erratic in accuracy.