I have a buddy with a nipple that came with his TC plunger gun (can't remember what model), that does the same thing. In fact his are so tight, he puts a cap on... then fires the hammer once to seat it down onto the nipple, then he's ready to shoot. The next time he drops the hammer, it will go off. Stupidest thing I've ever seen. LOL. I don't know if his is flared out some or what, but he's too cheap to spend $10 to buy a new one...so it makes for good fun for me to rib him about it every ML season.


I have factory knight red hot nipples in all my #11 guns, and I use RWS usually, and sometimes CCI/Winchester. Obviously the RWS are a tad snugger, but they both work perfectly.

The only solution I can suggest is to file down the nipple a smidge so your cap fits...or better yet, get a red hot.