If the can is not centered with the bore, how are they going to machine it to make it centered. I think that can is screwed. Replacement would be called for, let them sell the correction to the next guy.
Guys that say they have 52K rounds on hand and are still buying multiple case loads because they can. Doesn’t matter how well your firearm shoots if you don’t have any ammunition.
The problem I have with electronic ears is you hear everything in the damn woods. The second problem is you can’t tell where in the hell the sound is coming from or exactly how close it is.
If you are trying to determine which mag is bad, just number the mags with paint and a toothpick. Keeps from mixing them up and having to repeat the test.