Did not give full info. This is a hard taper crimp that is pushed into sides of bullet, so I don't see how pushing bullet down into case is going to break that crimp?

The other hint about hitting a harder surface is also null as I hit it on the concrete floors of my garage 5 hard blows and could not move it. I have used this to pull lead bullets before and know the amount of force necessary and this is over and above that.

The bullet collet puller just smashes the lead. Would like to save the bullets as well, but I may pull a few with the pliers method described just to check case volume.