When you're talking British guns is there really a difference between the gauges???
If you look around enough. you'll find some of the lesser known makers built guns that would knock your socks off concerning quality, fit and finish. Find one and pick it up and swing it you've never felt anything like it in a firearm, its feel in you hands can never be adequately described with any language and it doesn't matter what gauge it is!!!
The best description I ever heard about a British game gun was, your hunting in the woods and when a leaf falls from a tree a Brit gun wants to snap up to your shoulder and point at it!!!