Take a moment to read the instructions on yur kinetic puller ot look them up online. I bought the cheapest RCBS one and it clearly states to smack hard on concrete or steel, and also informs you of not using wood surfaces.
I think RCBS does that to sell more replacements
(That's a joke in case anyone didn't get it.)
I feel that using the end grain of a short 4x4 gives me a better inertial pull because of the rebound effect that the wood has. I lost my instruction sheet for my RCBS bullet puller decades ago.
I did find that if I try to give it a hard whack, the aluminum handle would bend, so I developed this technique:
1 Hold the handle loosely
2 Get the head moving VERY fast
3 Just at the instant of impact, loosen my grip even more, so that I am holding the handle by thumb and forefinger only (this allows the rebound to be unimpeded and cured the handle-bending for me).
I admit to a lack of experience pulling bullets. Aside from one "marathon" session wherein I pulled about 30 bullets, I have only had to pull a dozen others (including several 500 S&W with a heavy crimp loaded by a friend. But I think myself an expert because of the ease of those experiences. I am a legend in my own mind, I guess.
Lost Sheep