Loading 350 rem mag. Lee dies giving about .001 neck tension which was not enough to keep bullets from pushing into case with very moderate pressure. Tried a Redding die now getting .005. .376 sized brass .381 loaded round. Bullets seated a little harder obviously but not radically so by feel. I did have one case that was .375 or .006 under and seating force was extreme. Pulled that round. Question is how much velocity pressure increase from .001 to .005 neck tension? Running a load with Ramshot Tac that is at the low end of Barnes data.