What actually happens when a bullet hits a windshield? The video below runs a proper test: multiple calibers against automotive glass with high-speed cameras catching the results. The testing is theirs, not mine, but I’ve spent enough years around ballistics as a gunsmith to add some context. I’m Lance Rankin, owner of Western Sport in Roanoke, Texas.
Why windshields are weird
Side and rear windows are tempered glass, built to shatter into pellets. Windshields are laminated: layers of glass bonded to a plastic interlayer, curved and raked at an angle. That combination deflects bullets, strips jackets, and sends a cloud of glass along for the ride. Angle matters enormously; a head-on hit behaves nothing like a shot taken across the hood.
What the testing showed
.22LR: The surprise of the video. Fired from a rifle, it punched through the windshield intact, dragging plenty of glass with it. Don’t ever assume a windshield stops even the smallest rounds.
9mm: FMJ made it through but had its jacket shaved off by the glass. The hollow point actually did a bit better, expanding roughly as designed. The bigger takeaway was deflection: the testers note a bullet can wander anywhere from a few inches to nearly a foot for every foot of travel after the glass. Point of aim and point of impact part ways fast.
5.56: M855 green tip, with its steel penetrator, stayed largely intact and tumbled on exit, handling the glass well. The 77-grain OTM broke up more but still delivered a serious impact.
7.62×39: The AK round’s 123-grain bullet fragmented some but had the mass to push through convincingly.
.308: Fired from a SCAR-H, both M80 ball and 168-grain match went through like the glass wasn’t there, shattering it violently and sending fragments downrange at speed.
Shotgun: A rifled slug went straight through with minimal deflection. Buckshot pellets scattered and deflected like handgun rounds. If a shotgun has to defeat a barrier, the slug is the tool.
My takeaways
Three things stand out. First, glass changes everything: bullet construction that performs beautifully in bare gelatin can come apart on a windshield, which is why barrier performance matters when picking defensive ammo. My best 9mm self-defense ammo guide leans toward loads that hold together. Second, the glass itself becomes a projectile; anyone inside a car that’s being shot through is taking fragments regardless of caliber. Third, for a defensive rifle, this testing is another point in favor of 5.56 with quality ammo. It handled the barrier fine, and the capacity and recoil advantages over .308 are real. I dig into rifle choices in my home defense AR-15 setup and 5.56 vs 300 Blackout posts.
Last thing, and it matters: this is ballistics education, not a suggestion. Shooting at or from a vehicle carries enormous legal weight, and self-defense law around cars is unforgiving of bad judgment. Get real training before you ever need any of this, and know your state’s law cold.
Lance Rankin is the owner and Chief Gunsmith of Western Sport, a family-run Type 07 FFL and Class 3/SOT dealer in Roanoke, Texas, serving shooters since 2007. Born and raised in Texas with over 50 years of experience handling firearms, Lance purchased Western Sport in 2017 and turned his lifelong passion into his profession. He specializes in AR-15 and AR-10 platform rifles, manufactures Western Sport’s own AR-15 line under the Rankin Industries brand, and runs the shop’s in-house Cerakote coating operation. When he’s not behind the counter or the workbench, you’ll find him on his ranch deep into the night, hunting coyotes with an AR-15 and thermal optics. Lance holds an MBA and personally shoots and tests the products Western Sport sells.
