Generally, if you have to go a complete go around and then they fire on the second strike, the caps still weren't quite down all the way onto the nipples so the first hit seats them and the second hit crushes them enough to fire them. One way to test this is to put larger sized caps on the nipples, even real loose caps pinched out of round just enough to hold them on. If those larger caps all go off on the first go around then your first caps are too small for the new nipples. Solutions are either larger caps or go to factory stock nipples or some other replacement nipple like Treso or Slix-Shot.
Caps aren't standardized like primers. A CCI #11 is smaller in fit than a Remington#10. The Remington#11 fits way larger nipples than the CCI#11 and the RWS#1075. The Rem#11 is actually the same diameter but just cut shorter than the Rem #10 which is longer and thus able to grab smaller nipples farther down the tapered shank.
What size caps are you using? What nipples did you install?
With over 15 perCUSSIN' revolvers, I've been called the Imelda Marcos of cap & ball.
SASS#3302 (Life), SASS Regulator, NRA (Life), DGB#129
Wolverton Mtn. Peacekeepers (WA), former Orygun Cowboy (Ranger, Posse from Hell)