Have a friend with a 12 bore rifle choked gun built by PURDEY 100 years ago. As I was wanting PURDEY guns and they agreed to build it I proceeded. It is built on a rifle action with a set of smooth bore barrels for goose shooting. I have a 12 bore holland shot gun with a set of paradox barrels and a holland rifle 375 short with a set of 28 bore paradox barrels. It may take a while and I will report on loads and regulation etc.