What is the interior dimension of your 10-gauge chamber just above the rim? What is the diameter just above the rim of the existing fired cases that will fit? What is the diameter just above the rim of the fired cases that won't chamber? That would determine how many thousandths you would need to resize.

SAAMI spec is here, page 19: https://saami.org/wp-content/upload...shell-2015-R2019-Approved-2019-04-23.pdf

Diameter of 10-gauge 3.5" just above the rim is 0.854 - 0.009, meaning that your 0.846 is right about at the very smallest diameter possible. Not knowing the dimensions you're working with, If I were you I would try opening up the 0.846" hole to about 0.850" or 0.852" for the first inch or so and see if that takes care of the problem.