Bulletproof glass is obtained by bonding several layers of glass with. Polyvinyl Butyral (P.V.B) The P.V.B in this case is more of soft glue which absorbs most of the energy by the bulk of the glass which will stop the bullet from penetrating .the more layers and thickness will give extra strength. Configuration depends on the type of ammunition, distance of shooting and level of energy developed by the gun\rifle. The extra layers of polycarbonate will give extra strength and prevent glass from splitting all over.
The chart below shows the different weapons and the relevant thickness required:
Bulletproof glass is use of the following:
VIP Cars and Vehicles