Not my Dragoons but my Walker
When I got my walker I found it had more than one size nipples. One or two chambers misfired on nearly every shot because the nipple was not tall enough.
I replaced with Treso and use number 10 caps without further problem.
I do realize that you are having a different problem. My only point is that Treso nipples with 10 caps works with 777 and GOEX.
I don't shoot Pyrodex and it may be that Pyrodex requires 11s. Don't know.
My reading of history convinces me that most bad government results from too much government. Thomas Jefferson