Howdy 45 Dragoon.....aka Mike!
You're a danged cap&ball revolver genius.
You are right there in the right area of concern. I read an article about you in a Gun Magazine a while back. That was pretty cool. I saw something on E-Bay too with you showing yer shop.
Anywhoooo…..the thing I was looking for people to realize did have to do with caps all going off at one time if the safety pins were not filed off the cylinder and the nipples shortened by the height of the ring on the recoil shield of a Colt brass framer. You know....if a plate is soldered on where the caps normally ride they will hit the plate and all go off if the nipples aren't shortened.
The way it works out is to measure the thickness of the new little plate which is the same thickness as that ring on the recoil shield of the Colt type cap&baller revolvers. Then just shorten the nipple cones by that much. In the end there are no safety pins so the hammer should rest on an empty chamber.
Anywhooo….I thunk the manufacturers should press in a steel ring on the recoil shields of the brass framers. Better yet they should leave the ring off the recoil shield all together so the force of the cylinder recoiling is spread out Then have the nipples set a little deeper by about .025". Of course they might think of putting a pin down thru the brass and thru the arbor threads and into the brass a little to keep the arbor from pulling out the threads.
Anyway I can't post pictures to show what I'm getting at. It's not difficult to do if s person can file a little on the steel plate and solder it on and shorten some nipples. What makes it easier is to use the 7/8's by 1 3/8's 14 gauge narrow rim bushing sold a good hardware stores. I've got them at a hardware store and the tractor parts business near me. The narrow rim bushing has a large enough hole to fit around the ring on the recoil shield with a little filing. It ends up like the recoil shield is flat so the cylinder recoils back into a bigger area and doesn't dent the brass ring there on the recoil shield. When the dents happen the dents make for two cylinder gaps. One larger when the gun is in battery and a smaller one when the hammer is between the nipples.