I've been playing pool for about 12 years now and I've ALWAYS had an issue with my tips. I usually play moori/kamui mediums. But I'll shape my tip to a dime shape and within literally 30 minutes of playing, my tip is a nickel shape at best. Probably a little flatter than a nickel shape. I've never known why. I don't think I hit the ball hard either. I'd say I hit the cue ball at an average hit. I have to reshape my tip almost every night. Maybe I should go to a hard tip?