Re: Bersin Concentricity Tool
I don't think I would accept ten of them free. Their problem is they push the bullet back straight. Too much of the time when that's done, it loosens them in the neck. That's because the neck will also bend and become oval shaped at the mouth.
Crooked seated bullets are typically very well aligned with the case neck. To straighten them out, you have to bend the neck on the case. And do so without disturbing the bullet's position in the neck.
This can easily be done by using a bullet puller with a collet sized a bit larger than loaded round neck diameter. First measure your rounds for bullet straightness, then mark their high point. Put the bullet puller in the press, then push up a bullet in it from below with the high point mark towards you all the way to the shoulder, then gently tighten the collet a bit. Push the bottom of the round back a bit, remove the round then check its out of round value. You'll soon learn about how much to push the bottom of the case to straighten the runout a certain amount.