Voyageur,
I have no intention of using both at the same time and presently have no access to BP anyway, due to legal restrictions. Just wanted to know if it was possible.
You may note that I live in the UK and our firearm laws are far stringent and stupid than most countries in Europe. Presently, I'm only allowed one 45-70 rifle on my firearms certificate. To add another rifle in the same calibre or different would mean more forms, money, irritation of dealing with completely dictatorial firearms officers and several weeks(to say the least) of waiting. At the end of this hassle, I'll not be sure whether my request would have been approved!! Thus,if things got bad as that, the next best thing would be for me to borrow BP ammo from other BP shooters in the club and have a go at it with my present rifle that I shoot with nitro.
Kris