First up, here's what .45ACP 230gr FMJ does to 1/2" thick plexiglass.


Here's what happens when you hit aluminum blacked with a thin sheet of stainless steel.
that's 124gr 9x19 and 180gr .40S&W




Despite the higher energy of the .40S&W the larger surface area (not sure about velocity) reduced the penetration, I didn't bother with .45ACP. Still looking for someone with a 10mm or .357Mag to shoot it with, maybe a simple pistol plate?



Okay so we can stop some pistol calibers easy enough, and plates could easily be made... but what about intermediate rifle calibers?

Well, here's a composite test piece. Layered 16ga stainless steel, 1/2" plexiglass, 3/8 aluminum, then 16ga stainless steel again. Goal here was to slow the projectile enough that when it hits the last layer or two it stops it.



First up, 7.62x39 Tula fired from a SKS.


I had this propped up against a stump so it couldn't go flying reducing energy transfer and making it harder to locate. The impact side was the stainless steel then aluminum side, I wanted the projectile to be slowed down some before it hit the poly-carbonate / plexiglass.


Obviously the stainless steel and aluminum weren't stopping it, but here's the plexi.



Not sure if you see it but it went through the plexiglass, but that's the bullet sitting against the last layer of stainless steel, dented but didn't pass through.



So add some duct tape since the metal bands broke and I hit it with M193 from my 14.5 pinned and welded to 16" carbine.
Obviously passed through the first stainless, but wait what's that I can see down through the aluminum?

The bullet actually stopped between the aluminum and plexiglass, it's holding the two together.

Little twisting and pulling and it broke lose.




So then I wanted to see what just a whole inch of aluminum, layered would do, I mean surely it's harder than the plexiglass, but probably shears differently under impact, no way to know for sure without trying it so I made a little aluminum block comprised of 11 layers to make it just over an inch thick 1.03" thick. This time I would TIG weld them all together.

Well first shot was a little low since the carbine has a scope on it, I aimed at the top but just grazed the bottom. 2nd shot nailed her in the middle though.




Can't say I'm surprised, but I was a bit hopeful as cheap and easy as aluminum is to work with, oh well.


Well from this I'm considering making a larger piece of the composite that worked to stop the 7.62x39 and 5.56 rounds. I'm tempted to try changing a layer to fiberglass. What do you think?

When it comes to pistols there are lots of ways we can stop that threat using very gettable materials. For example, A 36x70 sheet of Kevlar k29 weave will make 21 10x12 sheets assuming no loss for cut areas. Three 36x70 sheets will make 63 pads or two panels with 31 layers each. That performs about as well as a IIIA panel and weighs less than 2 lbs per panel.
Personally i would be much more intrested in if you can make a composite rifle plate that has at least one curve and weighs less than a 1/4 AR500 plate.

Keep testing make sure to post in the handgun forum please as we there would find this interesting.

I wish we lived close I would loan you my Glock 40 and 31. Id like to test some of the silid copper bullets as well as hot FMJ.

Second the above. 

It's easy and relatively cheap to stop handguns. Rifle rounds are another matter. 

Sorry if I missed it, but what were the sizes and weights of these "plates"? 

Not sure what full sized plate would weigh yet.

Hey that's pretty neat, thanks for sharing.

All right I have an idea, that should reduce weight and increase stopping ability, but it's going to require my poor ass to spend a little money so might be a bit before I have anything to show. Pretty tight at the moment.

But next time I post something I'll make it a full size plate and weigh it. The goal is to be no thicker than 1" and no heavier but hopefully lighter than an AR500 plate while still stopping the same projectiles, but less than half the cost of AR500 plates, I'm fairly sure it's doable. Weight may be close to the same though, won't know until it's made.

What's your idea? Maybe one of us could try it out or have already done it.

Nothing useful to add OP, but thanks for an interesting thread.

There's some great DIY plates being tested on youtube right now.

Some interesting ones using tile flooring and magazines soaked in glue as I recall.

Overall it's cool to test, but you can get Level IV ceramic / poly hybrid plates for $135 now from RMA.

I was unaware of them and their offering. Well probably going to drive on forward anyway...just out of my own curiosity. I notice their level IV plate is 1" and 8.3lb and their level III is 1.3" thick and 3.3lb.

One thing I always remember...

As a kid, several of us went shooting in this area where they were going to build a subdivision, but didn't. Laying there was a rectangular cover for... I'm guessing now maybe an electrical or cable type underground service. About 1 foot by 2 foot. Looked to be made of some type of fiberglass mesh in an epoxy, been thirty years now.

That thing pretty much stopped everything we shot at it, and significantly slowed the rest down. Only like an inch and a half thick.

Point is, don't limit yourself. Remember that a lot of shock is being passed through your stacks, too. It does the wearer no good if it stops the bullet, but tears their aorta.

Also consider bullet destruction. That's what the tile helps do. Wonder if a fiberglass cutoff wheel would survive multiple strikes? 

Definitely got a few ideas left to try, pretty sure I can stop M193 with a lighter weight plate than what's discussed above. I'll post up results once I start the next plate, it's going to be closer to full size.


P.S. Anyone notice the ripple in the aluminum on the pistol plate from the .40 S&W. The 9x19 did it a little, but the .40 shows a lot more.

The bullet pushes material out of the way in all directions. It can cause kind of a bulge or expansion.