Windshields, auto and home

[USP45usp]

The "car hi-jacking" thread got my interest and I was wondering if anyone had done any self research or tests on how a bullet will either penetrate a window (side window mainly) or how it will act with it meets the window.

How about other factors? Like having tint on the window?

Wayne

[Vanguard.45]

I had the opportunity to spend an entire day "researching" this question at the police academy range where five old junk cars had been parked for "training purposes."

Side windows didn't seem to change the trajectory of the .45s I was putting through them, but the windshields caused a pronounced redirection of fire.

I placed a large silhouette target directly in front of the car and began firing COM shots through the windshield (new spot for each shot rather than firing through the hole from the previous shot). I can assure you that the results were not very impressive. In a life or death scenario where I don't have a second to exit my vehicle and where there are not crowds standing behind my target, then I would fire several rounds through the hole made by the first and just pray that the first "deflected" round did not hit an innocent.

I had heard that firing through the windshield would not cause much deflection, but that was not my experience at all. Side windows were not bad at all. Also note that it is very loud to shoot in the enclosed space of a vehicle.

Vanguard.45

[J 92 Brigadier]

During our intermediate CCW practice class last week we were told to hold the barrel up against the side window in order to send the force of the exhaust gases, sound and glass outward and away from you. The force of exhaust gases may be demonstrated by holding the gun barrel and shooting against an old shirt on a target. It makes a about a 3" hole in the shirt. We heard that there are classes for police snipers on how to determine shot position when penetrating a windshield.

[garrettwc]

I have not done any direct testing, but I have interviewed some people who have, and read up on some incidents where L.E. had to shoot into vehicles.

In general, the laminated glass on a front windshield will yield very poor results. In several instances JHP just fragmented without getting through the glass. The only round that consistently got through the glass was 230gr .45 ball, and even that did poorly.

The consensus is that your best bet is side window glass.

I have not read a lot of reports on window tint, but the recent shooting in Indianapolis involved them shooting both 5.56 from their M4s and pistol rounds from service weapons into a Chevy Suburban with tinted windows. The tint had the affect of laminating the glass much like the front windshield. I don't remember the exact round count (>12) fired, but the suspect was eventually hit with a pistol round that had went through a hole that had already been shot into the glass.

[Para Bellum]

I don't want to trigger another 9mm/.45 discussion, bit I think that bullets like 9X19mm or .357 Mag. will penetrate a windshield more accountably than larger diameter, heavier and slower bullets.

For a police instructor I learned that the angle is very important. Try to hold your gun in a position that allows you to fire at the windshield as close to a 90° angle as possible.

With regards to the carjack-szenario and my response posted there: The rear window of a car is not as solid as the windshield and not as flat in most cases. And you could also very well hit and kill a driver if you fire trough the trunk. The metal stands 90° to your line of fire, is on the level of the carjackers back and will under no circumstances stopp a 9x19mm or .357 Mag. bullet. Austrian Police shot several people throug their trunks with 9x19mm Glock 17s and a 115grs Bullet.

[garrettwc]

I don't want to trigger another 9mm/.45 discussion, bit I think that bullets like 9X19mm or .357 Mag. will penetrate a windshield more accountably than larger diameter, heavier and slower bullets.

I don't either. That's why I was careful to point out that .45 and 5.56 NATO rifle ammo had failures as well against windshields.

I think you are probably right about rear windows and trunk area. Not as steep an angle, and not as much intermediate material to go through.

I think the key as Vanguard mentioned and the IPD story I referenced show that it may take concentrated fire in a small area for the bullets to get through and do any serious damage.

[Jungle Work]

Bullets of moderate to large caliber willl penetrate car window glass if the shot is in the right place. Usually the 9mm on up will do better on windshields. Instructors from H&K used to put one a "Shooting Through Glass" Class. Very Good experience and information.

One of my friends was sitting in his patrol car when a person walked up to him and pulled out a pistol. My friend shot him six times with 125gr Federal Semi Jacketed HPs thru the side window glass. Perp was DRT.

Jungle Work

[Archie]

For a police instructor I learned that the angle is very important. Try to hold your gun in a position that allows you to fire at the windshield as close to a 90° angle as possible.

Okay, for me that means I'm either in a second floor window or standing on the hood of the vehicle. Especially if the vehicle in question is an SUV. Still, anything is penetrated better if approached at a 90 degree angle, rather than a 'skidding' shot.

Which in real terms means I'm better off shooting through the side, either windows or sheet metal. That is not good news if I'm the victim-elect of a runover assault. Not that life is fair.

Jim Cirillo designed a bullet for windshields. The front of the jacket was 'toothed' so that it dug in and penetrated, even at an angle. This same bullet was used as the 'pin-grabber' bullet for bowling pin matches. However, my agency does not allow me any creativity in ammo choices. I may only carry what I'm issued. Not that life is fair.

Penetration of a windshield type barrier is largely dependant on projectile velocity. So the 9s and 40s do have some advantage, in terms of penetration only. The .357 Magnum is better than both, as it has more kinetic energy and a smaller frontal area for what I call the 'icepick' effect. The .30 Tokarev, Mauser and Luger are also pretty good in this respect. The 44 Magnum with SWC bullets loaded to top level penetrates very well. (Go figure.)

Bullet shape also has some effect. Very pointed bullets do well, and wadcutter and SWC shapes both do better than gentle roundnose shapes. The (sort of) scientific explanation is the pointed and the sharp-shouldered projectiles cut the metal cleanly, whereas the RN tends to bend the metal prior to penetration. The net result is the RN spend more energy in the penetration process. This is true for sheet metal, and seems to have some relevance to glass, especially laminated glass with the plastic reinforcement.

Also note that it is very loud to shoot in the enclosed space of a vehicle.

Oh, yes sir buddy!

[USP45usp]

So, in relation to the car jacking post, if the BG did get the drop on you and has his/her/it's pistol against the glass on your side window, where it will take you about 1 to 2 seconds (or more) to draw, aim/point and fire, would it be better to take your chances and going for it or just giving the prep the car?

The reason that I kinda merged these two together is that I was almost a victem of a car jacking in downtown Valdosta (this was years ago, forgot to add that). I took the "short cut" to get to Wal-Mart (no wal-mart flames please) and had to detour over the tracks through a not so good part of town. I was stopped and a guy walked over and tried to "grab and get" my car. Luckily I had the alarm installed and got the extras such as door unlock with button, door lock when the car started, and the lights come on with you used the keyless entry. Since the locks locked when the car is started he "hit" the door handle and when it didn't open he quick turned and ran off into the housing area.

I was armed at the time (had my CCW for GA and the gun was between the console and the seat) and that couldn't have been a deterrent then because my windows are darkly tinted (around 30 to 35%). But, I still wonder what would have happened if he had a gun and demanded that I open the door?

About two/three or so years ago there was a report of an armed car jacking in the same part of town (close to it). I forget if the BG got what he deserved or not but IIRC he did and was shot (wonder also if it was the same person that tried to car jack me).

So, I was just wondering what I should have done and what I should do now.

Wayne

*mods/admins: If I have just made enough of a link to combine this thread with the car jacking thread then I think that it may be of better benefit if they may be combined if you wish.

[abelew]

Good question. I would atttempt to drive away (I leave a space in front of me to at least move foward enough to throw the BG off enough to grab mine)

[USP45usp]

abelew,

I did have space in front of me at the time but when I am stopped I used to take the car out of gear (stick) and then wait (I was waiting for a train or a stop sign, I forget which). I was in condition white at the time and just caught him out of my p-vision (I'm sorry, I don't know how to spell the pertural? vision) right when he was within 10 feet of the car and then my mind went into "[color=#FF0000]█[/color][color=#FF0000]█[/color][color=#FF0000]█[/color]" mode and by the time I thought about grabbing the gun, he had "hit and run".

In my defense, I was "new" at actually learning gun rules and gun art. I had gotten my CCW but I was not really trained on the conditions of awareness or that CCW was something really serious. The main board that I was on was shooters.com (I think that was it) where I got all kinds of great links to advertisments but not much knowledge and I was just beginning to subcome to the disease that is gun ownership and collecting .

Wayne

[LAK]

What Para Bellum, and Archie said.

I did not measure windshield deflection, but have shot up a number of expired cars at various times, and tried a variety of guns/ammo on a variety of materials over many years. Many people would be surprized at what little it takes to stop many pistol bullets - and lead shotgun pellets of any size.

[tintcutter]

I tint windows. I have about 20 years in the field. I have installed a fair amount of blast mitigation film on buildings and cars. I have a few points for you.

1. You may reduce solar energy by the cosine of the angle to the glass. Bullets not going through a 45 degree windshield but penetrating the mostly vertical side window also describe this phenomena. Heavy bullets in motion have higher retained energy and their penetration is effected by the angle but when the energy needed to penetrate is NOT exceeded by lighter bullets, they bounce away.

2. The 7 mil thick UVB layer of polymer in the laminated windshield glass of a vehicle is the same stuff used to make bullet resistant glass. This is not found in the vast majority of side windows of cars in the USA. The first layer of bullet resistant glass is typically quite thin, like a windshield, serving to start the bullet mushrooming, spreading its energy to lower the PSI. Alternating glass and polymer turns the system into a elastic catchers mit made of the hard mineral quartz and high tensile strength polymer. The more layers the merrier. Layered glass of 2 1/4 inches thick is typically level 4 and capable of stopping a 30-06 round. ( the UL test is three shots, six inch spacing, in a triangle). Incidentally, A 12 guage buckshot load is rated stronger, as the glass is broken, then penetrated by succeeding pellets.

[abelew]

I was not trying to say you were stupid or anything. I too have a stick, and am guilty of the neutral thing to get my food off the clutch. I only really practice that when the hair on my neck stands up (most likely because of bad part of town, or downtown).

[KC135]

Windshield, with 223 or handgun , you will likely have to chew your way in. As has been said, side windows are easier.

Trunk, with American cars, lots of stuff to go thru, might make it, might not.

[USP45usp]

abelew,

No offense taken bud. I didn't see it that way, was just explaining that I was more like a newbie on the issue and fell into bad habits.

, I am quite enjoying your replies on my posts as well as others, I took no offense at anything.

Wayne

[abelew]

have had some snide remarks thrown my way about my criticizm of the movie maker michal moore, and other comments I have made. Im kinda stubborn, and like "creative" discussions.