I'm not sure if this has been mentioned before but...
I have been pulling some stubborn lead bullets from 44 mag. brass using my Rock Chucker press. I purchased a Hornady universal ram extender (10 bucks shipped from Midway), and was grabbing the bullets with a pair of Vice Grips from the top side of the press. These bullets were old, and corroded. The lube had dried out and glued the bullet to the casing. To boot, these rounds had a decent roll crimp on them.
Long story short, the vice grip was damaging the 7/8 x 14 threads on the press. The easy fix is to install a Lyman conversion bushing into the press. Can pick them up on e-bay for a few bucks. The opening is still large enough for 44+ diameter casings, and the vice grips will only damage the top of the busing, not your press threads. Just an idea if you haven't thought of it already.