One of the biggest differences is the way the guns are choked. In trap, you are shooting at rocks basically going away from you, so a tighter choke is used to get extra range. In skeet, the rocks are more crossing in front of you so a more open choke is used. Also, the rib on a trap gun may be higher at the rear, sloping down to the muzzle so that an elevation lead is built in when the rocks are coming up out of the traphouse, you put the rock right on top of the barrel and pull the trigger. Other than that, any gun that fits and handles well can be used for either game.
bergie