Jeff, I read the article you referenced in the OP and your comments above. I was curious, so I thought that I would see what the internet says (this has to be true, of course!) about the performance of my carry ammo, Ranger T-series (examples:
and
http://www.everydaynodaysoff.com/2009/12/01/winchester-ranger-ammo-comparison/ ) through auto glass. (Caveats: this information may, or may not be repeatable or realistic in the real world, of course. In particular, the Ranger information may not be generally applicable to all, most, or even some other handgun projectiles. I'm not advocating Ranger T-series or any other particular product...I just mention it because it is what I carry.)
Based on this information, it appears that:
1) the .45 caliber projectiles fired by the perps (projectile type, velocity, and cartridge unknown) seem to have penetrated the officer's windshield six out of seven times.
2) A shot through a windshield left a lot of glass particles imbedded on the surface of the downrange gel block in the Twang-n-bang video.
3) The 9mm projectile in the video, after the lead core shed its jacket, penetrated deeply into the downrange gel block.
4) Winchester's tests on the Ranger RA45T (my particular carry ammo) indicate that this round expands to 0.58", retains 79% of original weight, and penetrates 12" in gel after passing through auto glass. The bonded version of this bullet ( RA45B ) retains more weight, and has slightly greater expansion and penetration.
5) The RA45T penetrated 16.5" and the RA45B 14.8" of gel after passing through sheet steel (of unknown thickness or composition).
I haven't done any first-hand experimentation on sheet steel or auto glass. I don't have a car in my back yard that I can go shoot. Nor have I taken one to the range or into the desert to test. You have done these things. I have no doubt about the strange things that happen to projectiles when they pass through glass, and especially reinforced glass.
If your point here
It makes little sense to shoot at someone inside a vehicle if you are going to have to punch through the metal, glass and plastic they are constructed from. Your chances of making a disabling hit are really dependent on luck
was that the trajectories of bullets are weird once they pass inside a vehicle, then I'm good with that.
However, it appears that at least some handgun projectiles can still pass through vehicle components and penetrate deeply enough into gel (and perhaps human tissue) to cause disabling, or perhaps even fatal injuries. These observations don't seem to be consistent with this statement:
What can the armed citizen take away from this? You are more protected then it seems in your vehicle. Useful information in a carjacking.
And there is no effective way to engage someone in an automobile with small arms.
Were the results of your testing very different than the video or the Winchester table? If so, can you describe what you saw? Are there other observations/experiences over the course of your career that led you to these last conclusions?
Help me understand (at least until I can get a vehicle or auto glass out to the range to see for myself!).