I just got my first gun, an ISSC M22 (looks just like a Glock 19), and I don't know if it's my long fingers, the angle of the grip, or the serrated trigger but my trigger finger hurts whenever I shoot the gun. When I pull the trigger most of the pressure is on the side of my finger (almost at the place where the side of my fingernail is). I also noticed this when I shot a Glock 17 but not when I shot a Beretta 92fs or a Sig Mosquito. Am I doing something wrong?