[rotorwrench]

I use cobalt drill bits. They hold up better. It helps if you are good at resharpening them too.

A person can use a grinder or a hand operated belt sander to reduce the heads but it has to fit in the confines of the work at hand. On Frame rivets, I've had to drill the buck tails when it's easier to access them. It works about the same way as drilling the head but the hole center can not be established as well. Rivets don't always mash straight down. They can be club footed at times.