I did my second casting session today. The new Lyman 2 cavity 338 RNFP 158 grain mold was better behaved than last time, but the screws keep wanting to back out. The sprue plate screw is the worst and I have tightened it so many times I am starting to strip the darned screw. Is there an obvious solution? Now that it is getting broken in the mold produces very nice boolits, but having to constantly retighten screws is a nuisance and ruins my casting rhythm.