No worries: I didn’t think your previous response was for me. I’ve never answered to “Dave” except to my Dad and one aunt, both of who have passed. For a few years I squadded at pistol matches with 4 other guys named Dave or David. We all quickly learned to ignore the derivative of the name that didn’t apply to us. Fortunately, we didn’t have to do any machine work to the barrels. It’s a battleship restoration so the breeches needed to operate properly and smoothly but they’ll never be fired again. They elevate and train like new now. We just finished all 6 of the 5”/51 caliber guns. They had to be finished before the ship is moved out of the dry dock; too big and heavy to put them back on the ship using a barge and crane. The dry dock has solidly mounted big cranes to handle that delicate job. Now it’s time to restore the remaining 3” guns and 7 more 40mm quad Bofors.Too many Dave's on here ! Yes , I understand what you're saying and I've done all of the above , and I've done many a BIG Barrel DoD guns . My point was from a newbie's perspective . Once you get the 29.5 procedure down , you can move on to whatever it takes . I can't tell someone that doesn't know his butt from a hole in the ground to do whatever works for him as he just doesn't know . I know wrmiller knows what he's doing , but unfortunately can't do the 40 tpi on his newer/older lathe .
Just to add . The barrel was threaded to size but not concentric . If the existing thread was picked up and threaded , it would be way undersized . Wouldn't trust that on any gun . May have to build it up and re-chase the threads for a decent repair .