Thanks. Yes, the only bit of soft solder that was there was in the front to close the gap between the ribs at the muzzle. Everything else was brazed. The top and bottom rib were brazed as well as the ramrod guides and the wedge slot. The barrels themselves have a flat surface milled on their side for their entire length. Near the breech this flat is quite substantial. Near the muzzle it is almost invisible. This flat surface is touching on the entire length of the barrels, but they brazed only the final 5~7cm or so (2~3in). The rest was held together by the braze in the ribs. Theoretically it would be possible to pound a wedge and split the muzzles after ribs were desoldered, but my barrels were already bowed inwards. I didn't want to add to that bow even more.

Now I have to find out if the barrels are bent only on the outside but bored true, or bent normally (inside corresponds with outside). So far I made two pins to measure exact groove diameter (.578~.579). I turned the pins on a lathe slightly oversize. Then I sanded them down until they fit into the muzzles. Next I plan to make longer version of those pins. How long? As long as I can make them in a consistent size. 15cm (6 in) being z minimum. Then I should be able to "feel" bends as the pin should bind in the barrels.

Also I need to find out the correct starting point for the regulation. In another thread about a fairly powerful DR build the author said he is starting the regulation with the barrels 40 thou nearer (center to center) at the muzzle that the breech. Pedersoli's originall "regulation" was approximately 4mm so 160thou! I'll start another thread in the build forum to ask. If I don't get any answers I'll have to make some sort of jig to be able to shoot the barrels prior to joining them to test.