I have a Wera torque screwdriver for ring caps, and the Borka kit for everything else. With the lower torque numbers for the scope ring caps, a screwdriver style is a lot easier to use.
Take a permanent marker and cover the entire case and bullet. See if it’s contacting anywhere when chambered. I just had the same issue with a 260 barrel. The neck shoulder junction was too big causing tough extraction.
I just purchased a new one from eurooptic. The price is painful, but it is a fantastic optic. The one you listed has the Christmas tree reticle and should be a little more desirable. I’d think a used one should easily fetch $3500.