Does anyone remember a modern blackpowder breechloader that fired single buckshot and used kid's caps for a primer?

I remember the rifle clearly and could have sworn it was made by the Rocky Mountain Arms Corp. Anyone have one? Anyone seen one?

I remember them too,and that was the maker,never shot one,but did look one over a long time ago.mid 70`s I think.they also made one in .22 caliber.look in some of the older magazines,you should see them.