Mike,
That's great. Did you see anything I could have done better, easier, etc?
Homelessjoe,
The ribs won't help much with regulating. Since the typical 12g has the muzzles contacting each other and the breach ends are not disassembled in this operation, not much convergence regulation concern is there. The main issue in this process is twist. It can be very easily twisted even when wired. I saw Andy _____witz do the leveling on the Shotgun Journal episode where Bruce gets his dad's M21 stripped and re-layed. I used this technique for my 20-28g conversion also and it is less sensitive than you might imagine. I check top and bottom and split any difference. It's a shotgun, not a rifle. If you get in the 10-15 MOA area or less you'll be so close I defy anyone to detect it shooting off-hand on a low gun mount at 40 yrds.
I'd say this job was challenging in that it was intimidating but not technically a difficult task. Heck, it's only soldering. Anyone that has soldered copper plumbing has the basic soldering skills to do the soldering part. Some understanding of the regulating process and using these techniques is about all that is required. Oh yeah! ...and some intestinal fortitude if the gun is a nice one. LOL
