Your "inserted barrel" project is most interesting-- what model and series Krieghoff do you have? TIG welding will stress the barrel pads and OD and maybe pull it out of round- Nicht zer Gut, Ja?-- I might try silder solder, as there is zero recoil with a .22 short cartridge--just a shot however-- Viel Gluck!!

"The field is the touchstone of the man"..