The RCBS inertia puller comes (or at least did) in the Rockchucker complete kit that lots of people including me started loading on.
~25 years later I still use it on occasion, and just the other day I was pounding out some 40 S&W loads that somehow missed getting new primers and I couldn't get the collet to grab.
I too bang them on the floor, at least to get started.
What's an STW?
Shooting Times Westerner.