Well I cleaned the .243 yesterday and went to check it this morning.
I took some 58 grn v max which I need to use up and my new Winchester to check.
Before I got to where I was going to zero a squirrel popped out the hedge 50 yds away , couldn't resist so popped in a 58 v max and ruined his day.
Zero seemed fine but put a few on the target and they were fine putting 2 rounds inside a penny at 100 yds and a couple touching at 150 yds , so happy with that.
So cleaning the barrel made no difference at all ...rifle shot the same.