Dave, many years ago, I sold a 3" gun to a local friend of mine, and he wanted a better system for firing it other than a linstock and slow match. So I made a lock that screwed to the end of the cascabel. But this gun had a removable cascabel breech for loading the charge, and I installed a nipple so a percussion cap could be used. The system was really effective. And in addition, I made an adjustable sight that slipped over a stud on a bearing so that no matter what attitude the gun laid, the sight was always dead centre on the bore. I know this is of no use to you, but your thread made me remember this guy.
