Glad to have you on board,
modestandrew.
As you take time to browse around TFL site, you'll notice there is a dedicated
Shotguns forum. There is a wealth of information available there, and some extremely knowledgeable scatteergunners frequent the place. I suggest you re-post your question on that forum - - You'll come a lot nearer obtaining comprehensive information in the specialized area.
Normally, it is frowned upon to do multiple postings in various areas, but this would be an exception. But - - Don't be a stranger on
Full Auto.
Best regards,
Johnny