Nothing that I can see on the barrel, apart from "16".
What if I measure the depth of the chamber with a caliper?
For it to take a 70mm cartridge do I need greater length in the chamber? At the moment, it measures 70mm down to a sloped lip in the barrel. It is not a stepped edge, but rather a throat, like in the cylinder of a revolver.
The Beretta is a Model 412, 16 cal if that helps...
Can anyone advise on the suitability of the cartridges I've bought? Good to go?
(Goodness!! Why can't a 12 just be a 12 and a 16 be a 16....