What size cap does your nipple take?
If it takes a musket cap, it will require a nipple wrench usually used on a musket such as a Pedersoli Enfield rather than a nipple wrench for a standard rifle nipple using #11 caps.
You may have to widen the slot on one of your wrenches and dedicate it to your rifle. Or you may want to get a nipple that fits your wrench. You could grind down the sides of your nipple if all your rifles take the same sized nipple.