I recently bought a used Knight Lk 93 and the nipple that is screwed into the breech plug seems to be a different size. This is the 4th Lk 93 that I've bought but none of my breech plug/nipple tools fit this nipple to loosen it...The nipple seems to be a different size...Can somebody let me know if nipple sizes are different and if so how many sizes are there? Perhaps someone makes a tool that fit multiple nipple sizes?...I dont know much about nipples being all my other knights are 209 ignition...