I bought a used Taurus PT99Af last week and upon taking the grips off to give it a good cleaning I noticed around the hole for the mainspring retaining pin was dents and marring like someone had beat on the pin to get it out. I tried to tap the pin out using a punch and ball pen hammer and it would not budge from either side. I noticed a cotter pin was used which is differnet than the Beretta Which uses an actual full pin. Does Taurus use cotter pins or is this something someone put in themselves? What can I do to get it out?