Make sure the gun is unloaded. Then back out the nipple a couple of turns and put a cap on it and see if it fires. If it does the problem is most likey the stop on the hammer. The hammer has a stop cast on the inside edge that hits the top of the lock so the hammer doesn't fly all the way forward when fired if there is no nipple screwed in or if the lock is out of the gun.
If the cap fires then screw the nipple in a little and try again until you start getting misfires. The amount the nipple is screwed out is the amount you will need to remove on the hammer stop.
And don't throw caps away that didn't fire because they were not struck by the hammer. You can also pinch the caps a little to make them stay on the nipple better. And I have never heard or read that the Crockett takes a #10 cap.
Good advice!
If the Hammer Stop or ledge on the side of the hammer that hits the top of the lock plate causes the hammer to be too far away from the nipple, one might be tempted to just grind/file that ledge so it will allow the hammer to go down further, but that means you will file/grind through the surface hardening. A huge problem comes in play if one does that and does not know how to correctly re-harden and anneal the hammer after doing that, though. If that ledge is not re'-hardnened/annealed correctly, it is going to wear more and cause wear on the Bridle that can/will crack the Bridle. Needless to say, I don't advise most people grind/file that ledge on the hammer, as they don't have the means to harden/anneal it correctly afterwards.
One thing more about the hammer stopping too far away is that it is possible the Bridle stops the tumbler too early and that will also keep the hammer from going far enough forward to set off the cap. (On one Italian Lock, it about drove me nuts before I figured that out!) I finally realized it when I noticed there was more room between the Hammer Stop ledge and the top of the lock plate than normal, when the Hammer was all the way down.
In the 70's and early 80's, I had to heat and bend quite a few Hammers "sideways" on UnCivil War Repro's, because the Hammers were not centered on the nipples side to side. However, after that time, the manufacturers seem to have mostly corrected that problem, but it is still worth checking.
The inside "face" of the Hammer that hits the nipple may also not line up correctly to hit flat on top of the nipple. To correct that the face must be ground or milled so it hits the top of the nipple flat. This is DEFINITELY not something the average person should attempt to fix, either. When we ran what was then called the "Navy Arms Booth" at the NSSA Spring and Fall Nationals, we usually would just replace the hammer when that happened, as that normally fixed the problem and was much cheaper than fixing the bad hammer.
Bottom line is that most of the things I have mentioned here should not be attempted by the average person and instead, the gun should be returned to the manufacturer to fix.
Gus
