Chopperlump: I looked this up in 'Winchester's Finest The Model 21': Page 59, "The idea behind Burton"s patent was to develop a new system of joining the barrels together that would be strong enough to withstand recoil forces and heat buildup due to rapid firing, while at the same time be inherently sturdy enough to be soldered instead of brazed, thus not destroying the heat treatment of the barrels.". What I think this means is the original heat treatment in producing Winchester Proof Steel and they felt brazing could anneal the steel due to the higher heat, but this is only a guess on my part as to the literal meaning of the above statement.

Socialism is almost the worst.