You will not get the maximum effect from a kinetic bullet puller if you strike it on a surface like wood that has give to it. Inertia pullers need just that...inertia. Any 'give' in the surface you strike them on reduces the inertia. I know it's hard to believe but you can whack the crap out of a kinetic puller on your concrete basement floor and it won't hurt it. Been doing it for years and probably pulled 1000 bullets with mine and it's still going strong. If the concrete is very rough the face of the puller might scuff a bit but you won't hurt it.