If your rifle is bad enough to require a barrel liner , then the liner would almost all ways show a improvement in accuracy .
True enough, but that wasn't the context of my question, which was more theoretical than the typical relining scenario to deal with a bad bore.
For example, NRA smallbore lever silhouette rules allow a relined original barrel, but not replacement. A shooter wanting to set up for optimal accuracy might try such a reline, even if the original S,L,LR barrel were in decent condition.
Thanks for all the replies.
Paul