Traditions Tracker #11 Nipple - The Thunder Nipple uses an 8mm thread that tapers at the end to lock into the Thunder Dome breech plug. This magnum ignition system assures you a torch-like flame to ignite the powder. (When using the 209 adapter you must use a magnum hammer.) See A1510 and A1512 209 conversion kits. Uses an 8mm thread that tapers at the end to lock into the Thunder Dome breech plug. Assures you a torch-like flame to ignite the powder