Ok, that also may mean that your dies may not work all that great for your new chamber, even if you buy new brass. Not trying to be all knowing, but if you buy new brass, on your 3rd firing you may get clickers and hard to extract.Yes. There are rub Mark's on the bottom 15% of the case. It's like it's not sizing all the way down using Redding dies.
I recently rebarreled my 6.5x284. All of my once fired brass from the old barrel will not chamber in the new barrel. It has all been full length resized.
It may give some insight by measuring the back of the chamber, a new case and a once fired case in said chamber and compare
You might be able to find a trim die just to see if it will full length size your brass. Not sure if they make one for your case but, worth exploring for a cheap fix. Your gunsmith might have to retrofit your chamber if, for some reason it wasn't reamed to the correct specifications towards the rear of your chamber, now causing excessive tightness on your casing. Just a thought.
I have the same problem with fired brass in a winchester mod 70 30-06