i think it's to do with the size of ur window. if not then its one of the sensitivity values.. i dont have hammer available right now coz im in college n my memory is terrible. when i made a really big window i "fit" the glass texture to it and when i shot it the holes were massive. if ur windows are bigger than avarage windows then try making them smaller.. if they aren't big then try messing with the values. soz i cnt be a huge help rite now.