Oh Oh here is a video about the "BEST British gunmaker", their words not mine. And their first claim to fame is that they glue their double barrels together. Because I have to yet watch the entire video I won't offer any comments

Gallyon's

Update: watched the whole video. Interesting. Nice stuff. Is it the best, that assessment would be far above my pay grade. Will the adhesives work forever? Well nothing is. I wish them well.