Purchased one of these impact bullet puller, its time consuming for my 223 but its better than nothing. When I try to use it with my 7mm mag (belted mag case) the belt eats away at the flat part of the collet and then lets a full round drop through. My solution was to turn the collet upside down and let the tapered end of the collet bite into the rim. It works but is this harmful in any way to the case? Any other way of making this work? And last but not least which press mounted puller would you go with?(deff will be ordering one tonight)