Does anybody know what method Beretta uses to assemble their barrels? Beretta has to be the premier maker for the use of true monoblocks.

I say "true monoblocks" to distinguish what is being discussed here. The method here is to take chopper lump, dovetail lump, or shoe lump shotgun barrels, cut them off in front of the chambers, ream them out to accept the shank of a rifle barrel, and attach the rifle barrels by some fashion. While the breach end of the shotgun barrels resembles a monoblock it is no such thing. It is an assembly itself, not an integral piece, as in a Beretta.

The point has been made that the heat required to braze or silver solder the barrel shanks into this assembly has the potential to cause the assembly itself to separate. Were it a true monoblock there would be no such risk. Of course, I am not addressing the issue of whether the heat might affect the strength of the steel.

I have read several books about building double guns (the real way, not "home made"), and in each account it is said that the maker brazes or silver solders the assembly at the breach, and then uses "soft" solder for the other parts (ribs, wedge, forend hook, etc.). The point is stated that the balance of the assembly process can proceed without fear that the joint(s) at the breach might come loose.

Interesting discussion here, although I will never be trying any of these things.

Regards,
Curl