[Tenacious 1]

Great story! (Sarcasm)

For those of us who know a thing about guns, what was the caliber? I didn’t know they made handguns that would fire rifle calibers.

The penetration for handguns is in the ammo not the machine itself.

[ltc8k6]

http://www.atf.gov/firearms/firearmstech/fabriquen.htm

batfe doesn’t seem too worried about the FiveSeven or it’s ammo.

[VRWCmember]

For those of us who know a thing about guns, what was the caliber?

5.7 mm, which is why it is called the Five-Seven.

[BobbyT]

It was the 5.7x28mm. Basically a .22 magnum. Comparing it to a rifle round is laughable.

With any round you have a set amount of energy propelling the bullet, and you can choose lighter, faster bullets or heavier, slower ones. The anti-rights crowd jumps on the velocity (high relative to pistols, nothing compared to rifles) and completely ignores the tiny round.

The 5.7 has energy levels in the 300 ft-lb range. By comparison:
- Old police .38 revolvers are around 250 ft-lbs.
- The smallest round considered viable for self defense, the 9mm, has around 400 ft-lbs.
- The other two predominant defense calibers, the .40 and .45, have around 500 ft-lbs.
- The .357 Magnum and .44 Magnum revolvers pack about 750 and 1000 ft-lbs respectively.
- The “intermediate” cartridges in the AK and AR that the media love to vilify have around 1300 ft-lbs.
- Actual rifle cartridges, like your boring old .308 or .30-06 deer rifle, fall around 3000 ft-lbs.

There’s nothing “armor piercing” about it. It will go through a vest, the same way that any rifle, most magnum revolvers, and a variety of pistols will, because vests are designed for light pistol rounds. The fabric just can’t handle that much energy.

[Oztrich Boy]

For those of us who know a thing about guns, what was the caliber?

5.7mm (.224")

You can either look at it as a lower powered reduced case 5.56mm NATO, or a centerfire analog of the .22 Winchester Magnum Rimfire