I have an important question about shooting bullet proof glass.
I was driving home from Target today and noticed they were tearing down a bank in downtown. I saw a large peice of glass in the dumpster and decided to go have a look. You see I do a lot of stained glass on old window frames, and this one was intact and looked pretty nice. So I went over and asked a guy there if I could have that large peice of glass in the dumpster.
He said, “Sure! Thats the Drive through teller glass! Bulletproof!”
Wow, I said. and proceeded to grab it with the guys help - as it was heavy - threw it in the back of the Avalanche and now I’m home.
IANA-Redneck. But I do have a couple guns. I was wondering what would happen if I shot this peice of glass with my Glok? Will it ricochet back near me? Or get lodged in the glass, or smash up and fall to the ground?
I’m not exceptionally brave when it comes to shoot’in so if someone could tell me what would happen I’d be pretty psyched. I have a lot of land and a huge barn so I have plenty of places to put the glass and have a baracade incase of a serious ricochet.
I’d for sure shoot it at an angle with a backstop of hay bales or something to catch the potential ricochet. Other than that cautionary point, I have no idea what to expect.
I urge you to stand far, far, far back if you indeed decide to discharge firearms into this piece of bullet-resistant glass. I know an installer who used to put that glass in, and he emphasized that shooting it at close range was near-suicide, or at least risky.
By the way, when the bullet hits, typically the top layer of the “glass” deforms, and then the next layer, but not all of the layers get damaged. When the first bullet hits, the entire thing is likely to become opaque.
The aforementioned installer mentioned that if you merely drop the danged things, sometimes the entire window would become opaque. One time a room heater heated the BR glass, and the window warped to opaqueness as a result.
The bullet should remain trapped within the material, assuming that it is rated to stop the bullet you fire at it (otherwise, it’ll penetrate). Every bullet I’ve seen fired into bullet-resistant glass has been trapped. (Note: My experience is from manufacturer demo tapes, not from any extracirricular banking acitvities. )
Generally, Lexan or other bullet-resistant materials will either deflect or imbed a bullet or shrapnel. The material is layered and very dense, and will generally stop a 9mm round without problem.
It’s also very expensive. A fully armored Cadillac such as used by the Department of State and armored by Hess & Eisenhardt runs around $200K a copy (or did; it’s been some years).
When the Ambassador to Guatemala was assassinated many years ago, the terrorists jumped onto the trapped vehicle and fired multiple bursts into the same area of the car window until the material was penetrated (or so I was told at a security briefing at State).
This must depend on the material that’s actually used. Bullet-proof “glass” is often a plastic material called lexan. It’s difficult to even scratch. I used to work at a sign shop, and would have to go to our plastics supplier to pick up material. On their front counter was a 2" think piece of lexan, with about a dozen bullets lodged in it. All of them were labeled, and ranged from .22 all the way up to fairly heavy rifle ammunition. They all penetrated to some depth, usually with some distortion of the lexan around them, obviously more for the larger bullets. In no way was the undamaged material opaque.
WOW!! I spent 2 clips into it from a distance of roughly 50 feet. the first couple deflected. I was behind an old tree - can’t be too careful. Then it splintered in circular ripples. Not one bullet went through, and I had enough of a mess to clean up. I was not brave enough to get closer. I can see this thing being effective at close range for a nominal amount of time. But as far as laying into it full on with an m-16. You’d probably be through pretty quick. However, whoever was behind it should have enough time to duck…
my dog was not too happy with me. He hasn’t come out of the barn…
An anecdote you might appreciate: IIRC I saw someone on Tomorrow’s World with one-way bullet proof glass. My first thought was “Man! You’d look stupid if you had it in the wrong way…”
I believe that it is true to say that bullet resistant glass owes at least some of its integrity to the manner in which it is mounted - shooting at an unmounted piece leaning against a tree may not be an entirely fair test.
The penetration resistant quality of “bulletproof” glass has more to do with the material construction than the material itself. Polycarbonate (Lexan is a trade name) is a type of plastic that has excellent properties for use in this application, but it is the composite layering of sheets of polycarbonate (alternating mean axes of the polymer chains) that stops the projectile. The individual sheets deform, and the composite delaminates, which absorbs the energy in the projectile. In the same way that bulletproof vests use multiple layers of high strength fibers to absorb the energy of impact, plastic composites can be constructed with glass, kevlar or carbon fiber reinforcements which act to distribute the stress of a bullet impact over a larger area within the window. The closer you can get to using the cumulative strength of the entire window, as opposed to the region immediately surrounding the bullet, the better chance you have of stopping it.
