I have started construction on a new double rifle. The barrels will be chambered in .45-120. I am using a very nice old case-hardened shotgun breech that I picked up in Tulsa just for this project. The barrels will be delivered in about two weeks and the chamber reams will wait until I have completed the rib. I will be able to fabricate extractors to function with the cases. I do not know if silver solder will be strong enough to join the barrels to the rib; does anyone have any information on this?