I found the cap guards(lil pink things) here under loading accessories under RMC products. Item #ML1084www.rmcoxyoke.com
One nice fact is....the pink lil thingies help stop frags of the caps and the danger thereof. They keep the caps on the nips. Go on really easy.
Those not wanting to modify their guns and do it the easy way the pink things are helpful.
The mechanical cap guards are cool but....there are still fragmentation of caps that can hang the gun up other places besides going in the hammer channel. They are good fer solving some of the problem but not all of it. The lil pink things(cap guards) solve it all. The draw back they cost a lil over a coupla bucks per 50ct.
My idea of a cap guard that was mechanical and solved it all would be the rear outside of the cylinder turned so a band of steel could be press fit and maybe screwed with a coupla lil screws around the outside rear so there was no opening above the cap/nipple and a thin backplate integral with a block in the hammer channel where a firing pin(sorta large diameter and flat on the end to hit the caps) with a spring(like a Richards conversion) to retract it and....there would need be a gate to the loading channel and.......and the nips would need stoned a lil shorter or sunk in the cylinder a lil to avoid chain fire against the thin backplate. The firing pin would need be sorta long and the block where it was mounted in a lil long too since the nips are sunk in some(further from the recoil shield). The hammer nose modified accordingly.
Therefore there would be no way for a cap to frag or whatever or come loose and get out of its own lil compartment and hang anything up. Then the gate opened and the spent cap removed by the operator of the shootin iron. The modification would look sorta like a cartridge conversion.
I thunk it could be made to work.
Worth it? ....... I thunk so.
It would be a lil bit a work but not really way too much.
Anyway I'd say that it would be really good if a company actually made a percussion cap that stayed put and didn't frag apart when ignited. That kind of cap would be ideal for Cowboy shooters.