Good advice Raimey and I plan to do that but from a learning perspective I'm curious about what the actual markings meant when the gun was made. For example, on barrel #3, for the RB ("17.0 choke 16.9") does it mean a 17.0mm bore choked down to 16.9 mm with the LB ("17.2 choke 16.9") being 17.2mm bore choked down to 16.9mm? Seems strange to have different bore sizes (neither of which are nominal for a 16 ga.) choked down to the same choke, which is pretty much a nominal 16 ga bore. If it is the other way around then the barrels are starting off with nominal 16 ga. bores but are choked more open and not more constricted.
In any event, I know I need to pattern the barrels but I'm trying to learn about the various sets of barrels' markings and what they meant when the gun was made. Many thanks for your reply.
