What type of metal (thickness, alloy etc.) can stop most bullets (9mm through mag)fired from an avg distance. ?

Question

i'm stripping down my interior in my 72 buick skylark. for my own reasons i need to increase it's strength and security.

my plan is to take off the door panels and reinforce them with some welded in metal plating. i'll also eventually do the fenders quarter panel and trunk. i thought about draping kevlar but hear that it was more expensive.

i've also hear bulletproof glass is expensive so my alternative is to take off headliner and install slide down sheet or plate metal to protect most of the windows in unfortunately difficult situations.

later on i'll want to re-inforce the cars body/frame to increase the strength. so it can take impacts without it bending the frame.

if there is a better way of going about doing this let me know. but i am doing it myself at home i have the tools i need tips on materials and methods.

Answer 1

Note that the discussion so far involved handguns - rifles are a different story.  They have much more power, so ordinary soft steel isn't going to be very good until you get thicker than 3/4", and even then assuming they're not using armor-piercing ammo.

If you want to study this field, check into what people have done to provide armor on tanks.  There are some tricks that can be done with double-layer armor that get the bullets to tumble/deform on the first layer, so won't make it through the second layer so easily.

There is another material that is a multilayer high-carbon/low-carbon laminate that has 200 ft-lbs of absorbing force - provides light weight armor with incredible impact strength.  

They also make transparent glass that is a polycarbonate/sapphire laminate that will stop a rifle bullet.  While it stops the rifle bullet, it cracks the material enough you won't be able to see out anymore, but it will stop the bullet.  It works by deforming/flattening the bullet nose on the sapphire layer.

These countermeasures are expensive.  The countermeasure the person needs to take to get around your improved armor are cheap.  To get through armor plate, you just need armor piercing ammo.  If you make the armor thicker, the armor piercing ammo just needs to be fired with more power.

You're really designing a tank - you should consider starting with a junked one-ton truck, stripping the cab down and putting armor inside that.  Also, take a look at what fighter aircraft/combat helicopters do to protect the pilot - they use a ceramic/titanium tub.  Would be cool if you could find a junked combat aircraft and pull the parts.  The other alternative is buy an old Brinks "armored car"/truck.   A lot of the work is already done for you.

The goal is to get you out of immediate trouble - one shot through the radiator is going to cause your vehicle to come to a halt in about a minute or three - hopefully long enough to get you out of harm's way.

Answer 2

What you are going to fight in all this is weight.  Slapping alot of steel will quickly take your car over its gross weight allowance and destroy your transmission, brakes, frame, chassis and suspension.  For a good example of this look at the up-armored HUMVEEs in IRAQ, slapped on a couple thousand pounds of steel and they all broke down in the first couple of months

To stop handguns of any type you are best off with ballistic fabrics like kevlar and spectrashield.  They are somewhat expensive but you can buy rolls of them and fill inside the doors with panels and the roof and such, even under the floor for mines/grenades.  This is how most all armored vehicles are done.  It keeps the weight down so you don't have to beef everything else in the car up

Might also consider run-flat tires, would make getaway much better

As far as how much steel to stop a handgun bullet, takes about 0.75 inches of high-hard steel to certainly stop a big solid core round.  Steel is  6g/cc so a sheet big enough to cover your  side doors (like 6 ft by 3 ft x 0.75" thick)  would weigh 450 lbs, so imagine bolting 3 or 4 of these on, your car will groan under the weight.

Answer 3

This would also depend on the type of slug used (hollow point), and if they are using a FMJ or not.

The stopping power to weight ratio of kevlar will pay back for itself in time (epsecially if you pay the same price for gas as everybody else). Not to mention that you'll probably want to be able to move if you are being shot at....so loading up your vehicle will make that a serious issue.

Not to mention that you'll likely wreck the vehicle on the first high speed turn you take.