The air-gun bullet marks on the glass are different from those on the other shots.This is because although the air gun has rifling, it uses spring compressed air as the power to launch the warhead, which has the advantages of low speed, low energy and light weight (0.5 grams per air gun), so when the air gun hits the glass, it acts on the glass for a long time and the force is small. The penetration ability is small, and its glass smashing marks are also different from those of stone glass.
The most accurate restatement of the main idea of this passage is that the marks of air guns breaking glass are different from those of other guns.