I have the RCBS collet puller. It works very well on semi jacketed soft point bullets, but absolutely does not work with cast bullets. I also have one of those hammer type pullers. I used it once. Gave up after just 3 bullets and hung it up on the wall. Only method I've found to be sure-fire with cast bullets is a pair of side cutters. Yes, the bullets are damaged and not reuseable, but they still melt down and can be cast again.