Sun tiger, I prefer the slix shot nipples. I purchased nipples from Track of the Wolf and the size of the nipples varied a lot. Some caps were easy to put on and some didnt fit without a lot of pressure. No problem with the slix shot nipples using the same caps. I also have the stock nipples. My #11 caps are loose on them. When #10s are available again Im sure they will fit on the stock nipples.