Niederlander: I've found that CCI #10's are are on the tight side for most stock nipples found on Uberti and Pietta Cap and Ball's. ie Dragoon, 1860's, 1851 44's, and Remington. I know for a fact they fit tight and won't seat on my Uberti 2nd Model Dragoon stock nipples. I bought 500 of em a while back and haven't shot a full tin yet. The only thing they fit on is a spare cylinder for a '58 Pietta Rem I bought several yrs ago. If ya want to read the 'who's who' of brand type of various caps and their relationship to various nipples, read Mako's post on the 'Darksiders Den'/The Dark Arts titled "Cap Gun Primer: Correct Cone Length". Alot of info and good reading!!!! As I posted previously, I've found Rem #10's fit the bill for all my needs with the guns I mentioned, plus a '51 Colt 36 cal (Uberti). I've never tried any Rem #11's of current manufacture, just some older ones from the 1980-early 1990 time period, they were too sloppy!