I am trying to find a spare nipple to buy for my rifle and I though about the hot shot (for number 11 cap). I have seen all sorts of nipples ranging from musket to number 12 etc.. What is the difference between all of these? Size? If I am buying a new nipple is this a time to change from the number 11?
I have had a few problems with the number 11 due to operator (rookie) mistakes but nothing that was the caps fault.

Thanks
Eric