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Posted: 7/25/2001 11:30:34 AM EDT
A few days ago, I was in a post office in NYC and noticed they had installed what appeared to be bulletproof (or maybe just resistant?) glass. It was about one to one and a half inches thick. I've also seen this stuff in banks, convenience stores and liquor stores once in a while. It got me wondering though, what is this stuff made out of and what's it rated for? I'd assume it would stop any pistol round, but what about rifle? (No, not thinking evil thoughts, just curious)
Link Posted: 7/25/2001 11:35:05 AM EDT
bullet resistant glass (never proof) is multiple layers of different polymers. THere are different grades which are usually just a factor of thickness. I have seen many different kinds but never one that would stop a rifle round. If you bonded enough layers together you could stop a rifle round but it would probably begin to distort visualy. They are usually rated up to 357 mag.
Link Posted: 7/25/2001 11:49:12 AM EDT
From your description, that was probably Lexan. It is sort of a really tough plexiglass. Stops bullets (and other things) very well but, like plexiglas, it is sensitive to UV and can degrade if exposed to the sun. For applications around your car or house film-type products like [url]http://www.shattergard.com/[/url] are more cost effective and much easier to install. These come in different levels and range from safety stuff that is simply keeps the broken glass from getting all over the floor, to bullet proof stuff, to some really expensive stuff that stops incoming rounds but allows outgoing stuff to pass through.
Link Posted: 7/25/2001 12:24:10 PM EDT
Most bullet resistant glass is referred to as polycarbonate. I thought I read somewhere that the Whitehouse windows were rated to stop a .50 BMG? I cannot recall the source. It is my understanding that the resistance is proportional to the thickness of the material.
Link Posted: 7/25/2001 12:28:01 PM EDT
Link Posted: 7/25/2001 1:12:52 PM EDT
Link Posted: 7/25/2001 1:55:27 PM EDT
There was some technology show on the discovery channel (I love that channel!) a while back that got on this subject, some new laminated glass and lexan hybrid that was amazing. They shot a it with 2 full mags from an mp5 on full auto at about 10 feet, it just absorbed the bullets, and I don't think any penetrated more than halfway through the 3/4" glass thick pane. Then they shot it with a .308, same thing, but it bulged the backside a bit. Then they had a guy hack at the piece that the mp5 shot with a fireaxe, he got through it after 7 or 8 whacks, but only enough to get a hand through, which would shred your digits if you tried, I think. They said the lamination was designed to separate and absorb the kinetic energy of the bullet, which it did handily. I was wondering how effective a trauma plate of this stuff would be.
Link Posted: 7/25/2001 2:02:57 PM EDT
A friend of mine had some (I dont know where he got it) we took 6 pices about 12X12in, to the range to check it out. At about 15 yards it did pretty good with handgun rounds. We ussed 9mm and 40cal on it it would cip it away and after about the 10th round it would crack and after about 15 rounds it was gone. But with a Rifle round 7.62x39mm it shattered with first round. 223 took 2 rounds to shatter it but first round went through and brok it up pretty good. This is waht I saw agenst the Bullet proff glass. So after that test I would trust it in most situations most bad guys arnt going to emty a mag into it or carry a rifle to a robery. SCAR
Link Posted: 7/25/2001 2:25:54 PM EDT
Usually, banks and liquor stores only use very thick acrylic about an inch thick. The reason for this is that it will stop most handgun rounds while still having the clarity of glass. Polycarbonate or Lexan (same stuff depending who makes it) is much more impact and shatter resistant but is not as clear as acrylic. The really good, most comonly used stuff is usually a combination between the two being a 1in peice of acrylic between a 1/8in piece of polycarbonate on both sides. Polycarbonate is only clear at thicknesses under 1/4in. I have shot at some of the really good stuff with a .44mag and it bounced off. A .223 and 7.62 round is a different story though. Both of them went through but veered off at an angle which was really fascinating to look at afterwards.
Link Posted: 7/25/2001 5:02:33 PM EDT
Lexan is the GE (General Electric) brand name for polycarbonate. Pexiglass is harder and more resistant to surface scratching, and more rigid but obviously breaks more easily. If you install Poly next to plex and put them through regular cleanings, you'll notice the poly will tend to scratch and degrade on the surface much more easily. It is susceptible to UV breakdown but can be manufactured to resist this. To cut it in sheet form you need to use a triple-chip blade. It routes and drills quite easily. To defeat it you could use a torch, flammable liquid, saw or cutting tool, drill or repeated hits in the same spot.
Link Posted: 7/25/2001 5:10:22 PM EDT
[Last Edit: 7/25/2001 5:07:25 PM EDT by SGB]
Link Posted: 7/25/2001 5:23:16 PM EDT
Originally Posted By oneshot1kill: The guard on the passenger side got out and cut in front of my friend who was waiting on line for a slice. An argument ensued, ending with the guard cursing us on his way back to the truck. Then the guard dropped his soda inside the truck. We were laughing really hard at him now, and the guard with no apparent reason pulled out his .38 revolver and held it up so we could see it. He was trying to scare us away. The next thing that happened was the gun accidentally discharged inside the armored car!
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BWAHAHAHAHA! What I wouldn't have given to have been you friend that day! As bad of an idea as it is to taunt someone as obviously gun-crazy as this guy, I would have had to have made a big show laughing so hard I fall on the ground beating it with open palms and kicking my legs! And as for the rudeness he did in the line, this result was I'm sure even sweeter to you two than even the best revenge...well whatever level of revenge is normally carried out for line rudeness.
Link Posted: 7/25/2001 5:27:33 PM EDT
My buddies wife is an archetec (sp?) and she gets samples of bullet resistant glass often. I've seen it deflect a 7mm Magnum 175 grain bullet. It then was able to take 10 rounds of .40, 5 of 9mm and countless .22 before a 7.62x54 finally went through, although at that time it was almost totally cracked and ruined. [):)] NSF
Link Posted: 7/25/2001 6:22:43 PM EDT
Someone was kind enough to leave a large piece of it at one of the ranges I frequent. It was heavy. about 2 inches thick. I spent the afternoon firing into it from different angles. The .380 and .22 bounced off. The .9mm stuck in, and the .223 and 7.62x39 went clean through, hardly slowing. In fact, at extream angles or sideways, the .223 penetrated 6 to 9 inches before disintergrating. The ss109 worked the best.
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