Yes, you need to make changes to the config.cpp file. Here are the lines that you are looking for:
hit=50;
indirectHit=25;
indirectHitRange=10;
Those numbers are just an example of what you can put there. With the numbers that I gave you, the weapon will do 50 points of damage with a direct hit. It will do 25 points of damage to anyone within 10 meters with an indirect hit.
Hope that helps.