Which primer is placed directly on the nipple of a caplock muzzleloader?

The #11 percussion cap is specifically designed for use with caplock muzzleloaders. In a caplock system, the primer is a small explosive device that fits over the nipple, which is the outlet for firing the charge within the barrel. When the hammer strikes the cap, it ignites the explosive composition inside, producing a spark that travels through the nipple into the main charge, igniting the powder and firing the round.

This type of primer is compact and ensures reliable ignition, making it particularly suitable for caplock muzzleloaders, which rely on percussion caps for their operation. Other options, such as priming powder or different types of primers, do not serve this same direct function and are not specifically designed to be placed on the nipple of a caplock firearm. Flint is related to flintlock firearms, not caplocks.