The concentric rings as per the picture in the O.P. start way down on the pilot where the brass case would not be making contact. My guess is thoese concentric rings as evidence of a poor finish on the pilot, not worn-in by the brass.It's possible that because the brass is softer, it would hold on to carbon / grit and when spinning it over the pilot it wears concentric rings into it.
So far I only spent about $20 to get some different pilots. But that is about as far at I am willing to go. Redding is sending me a new cutter head. I suspect that is part of the problem too. I am only getting good shavings off of 1 of the 4 tines. If the new pilots and the new head don't fix the problem it will be looking for a new option.I still think it's more the amount being trimmed off then the trimmer or pilots them selves . When I trim my LC once fired cases using a small base die . I've had to trim as much as .018+ off at times . That inside edge/cuttings that stays hanging onto the case mouth that we need to de-bur/chamfer always got hung up on the pilot and would roll up in between the neck and pilot . So much so at times the only way to remove the pilot was to remove the case from the trimmer with pilot still stuck in the neck . Then use pliers on both the case and pilot to pull them apart often ruining the case .
My honest advice is switch to a different trimmer before you've spent enough trying to fix your trimmer you could buy another and the problem still not be fixed .
An old priest and a young one were walking the road. Their order did not allow them to deal with women in any way.
They came upon a carriage wreck where a young woman had been thrown into the mud and was struggling with the impact of her being thrown and clothing saturated.
The Young Priest went around.
The Old Priest got her sitting, made sure she was ok, got her upright and carried her out of the mud hole to a good resting spot under a tree, then waited for another carriage to came along to give her a lift to the next town.
As the two priest proceeded on their journey, the young one berated the old priest about having violated the edicts the order.
Finally the Old Priest looked at the young one and said "are you still carrying that woman?"
I tried the shoulder trimmer method. I had trouble setting it up, and inconsistent results. Thus I decided to try the Redding. The results are much more precise, however it is having functional dificulties.Parable of the Two Priests (Buddhist I believe)
Shoulder Trimmer
I really like the wilson trimmer. but with over 5k pieces of brass to go through It is not a viably system.The Wilson trimmer actually has different case holders for resized and as-fired cases, so people do both. The reason you normally resize first is that cases usually don't all grow much until you resize them, and then they don't all grow the exact same amount when you do, so your cases come out long and a little uneven. However, the chamber specs normally allow enough wiggle room that this doesn't present a danger as long as you trim at some point during each loading cycle.