Multiple impacts do degrade the performance but the calibre of bullet is also a factor. The video was using a .223 (5.56mm) which is pretty standard for AR15 de

Multiple impacts do degrade the performance but the calibre of bullet is also a factor. The video was using a .223 (5.56mm) which is pretty standard for AR15 derived assault rifles. A slightly larger 7.62mm round will have more force and might be able to penetrate the glass. Bigger rounds like .338 lapua or a .50 cal would have even more energy and be more likely to penetrate the glass, especially if it was weakened by previous impacts.