Bought my C model QAS second-hand. My first time firing had shot grouping to the right of target area. Disappointed, but I noticed that the front dove-tailed sight was slightly to the left of center.... So that explains that. What would be the best way to finely adjust the front sights? And I also have a roll pin extruding out...More so after firing. What would be the best, or easiest, way to tap back in? This is my first handgun purchase. Any help would be very appreciated!