.333 is hefty! for an original .326 bullet but I suspect it was working once.
PRVI make a 208 grains softpoint for the austrian /hungarian 8x56R that should measure .330
https://www.prvipartizan.com/search_rbl.php
this could be the right stuff for your rifle.

you maybe have a problem with your die set when loading such an oversized bullet./?