During a recent shooting incident reconstruction class instructed by Forensic Science Consultants, we had some time after hours to perform preliminary research on our critical angle project. We found that automotive tempered glass resists 40mm less lethal projectiles at angles shallower than 90 degrees. 40mm impact munitions are sometimes used to break windows during operations, but the round must strike nearly square to the window to breach it consistently.
Come see a presentation on this topic at the AAFS meeting in Seattle, Thursday February 22!