Every time the 5.7x28mm cartridge comes up in a discussion, you always hear someone talk about its ability to penetrate a row of Abrams tanks and then continue on into the next county, but there is not a lot of information out there to prove the manufacturer’s incredible claims about the round’s ability to penetrate armor. Of course the commonly available sporting rounds, such as the hollow point SS195 or the blue tipped SS197 are not touted as armor piercing ammo by FN, but the mean little SS190 FMJ round is. So for this test, both SS197 and SS190 were used in a Five-seveN pistol and an AR57 rifle with a 16 inch barrel against a surplus kevlar helmet and a level IIIA US Palm vest to see if the 5.7x28mm round can in fact defeat armor.

Here are some mean little SS190 rounds. These rounds are restricted for sale to government bodies and law enforcement agencies by FN, which is why I conscripted my friend Chris to help with the test. Chris is an Army reservist, an FFL/SOT, and owner of Campbell Defense so I was happy to have him out there to help with this experiment.

So first we loaded the blue tipped SS197 sporting ammunition in the pistol. Chris is here standing and ready to fire. Again, this is not the armor piercing ammunition…

…and as such it did not penetrate the helmet:

What about SS190 FMJ from the pistol?

Consequently, it also failed to penetrate the helmet!

Well what about a rifle? The 16 inch barrel surely helped the velocity of the round. Here is the sporting ammunition:

And again, it failed to penetrate:

Next up is the armor piercing stuff from the long gun:

And boom, the round did make it through the helmet!

So the helmet held up surprisingly well to the round, but what about a new, unexpired IIIA vest with 4 years of life left? Well I was really excited about this one and I set the armor up on a cinder block. We would be shooting through the block’s hollow cavity to see if we could penetrate both sides of the armor:

So first up, Chris took aim against the rocky security guard with the pistol and sporting ammunition:

And we had a direct hit:

However the sporting ammunition failed to penetrate and was successfully stopped:

Next up is armor piercing ammo from the pistol:

Another good hit this time:

And with the armor piercing ammunition, the round DID penetrate the armor on one side, but flattened out against the backside!

So with SS190 armor piercing ammo, the round did in fact defeat the armor. As for the long gun, we first decided to try the sporting ammuntion:

And the armor did not stand a chance. Even with sporting ammunition, the round went through both sides like butter:

So that is that for the 5.7x28mm penetration test. To surmise:

• SS197 sporting ammunition from a handgun will not penetrate IIIA armor
• SS190 armor piercing ammunition from a handgun will defeat soft body armor
• 5.7 from a 16″ barrel will slice through body armor, but only FMJ will defeat stronger stuff
• Surplus German helmets are really, really strong

Pretty cool stuff. All in all the 5.7x28mm round when used with ammo not readily available to regular folks has some really nifty armor defeating capabilities, but be wary of those who exaggerate its performance.