Conventional chamber sleeving is pretty much only done to guns that are unsafe to use as is, due to pitting, other wear, or metal removal in the chamber/forcing cone area. I ran into a 12 that had been chamber sleeved down to 20 at a show years ago and had a nice discussion with Kirk Merrington about the procedure, a few days later. I’d never seen it prior.
As I recall, generally the gun will be safe to use again, and the plastic wads seem to seal just fine, and patterns are good. Value takes a hit, but, you have a gun you can use again. I don’t recall anything about Loc-Tite in the discussion with Kirk, but, it was a long time ago.
The procedure seems more geared to guns that are at end stage of usefulness, I doubt anyone does this to a gun sans issues of thin barrels that lead to questions of safety.
Best,
Ted