I was not to keen on drilling/reaming the arms all the way through. Like someone mentioned, the pin will go in nicely if only inserted into 1 ear at a time. That got me thinking and decided to try something different. I got my #19 drill and only drill 1 ear out but left the other alone. The amount of material remove was just enough to get the pin to almost fall through but still had that just right feel. If you decide to do it this way try and do the same ear side on both arms. If you still feel like you need a bit more clearance try a #18 drill next. I did not run the drill fast in forward. As I was drilling the drill was being pull while cutting at the same time if that makes sense. I then ran it backwards full throttle to get a polish effect. I really liked the way they turned out with this method.