5.7 Handgun..........

[Ray_Air...]

Does anyone know a place that sells the Five-Seven handgun by FN? It shoots the 5.7x28mm round. This is an awesome handgun and I cant find one.

I held one of those "hand rifles" just the other day. That thing is amazing!

Although, the ammo is pretty frikkin expensive.

[JoeSixPack]

I'm not familiar with the 5.7 but I have been looking at the Kel-Tecs.

Here is the PLR-16 with optional accessories. Definitely a "hand rifle", shoots common .223s although it is not at all concealable.

http://www.impactguns.com/store/640832000375.html

[ragnar]

http://www.impactguns.com/store/818513002509.html

[Antiochus Epiphanes]

pretty hi-vel rounds, no? what is available?

The ammo sold in USA is different from European round due to all the "cop killer bullet" nonsense. So you are, in effect, paying big money for a popgun.

[Ray_Air...]

Originally Posted by New Order

The ammo sold in USA is different from European round due to all the "cop killer bullet" nonsense. So you are, in effect, paying big money for a popgun.

The 5.7x28 round has a velocity of 2,100fps. Soft body armor is only "rated" to stop up to 1400fps. I have seen Level 2 armor stop a Tokarev 9mm round, but barely. Also in some of my tests 9mm Magsafe penetrated a Level 2A (16 layer kevlar)vest and penetrated 18 of 22 layers of kevlar in a Level 2 vest. Also 9mm Corbon Pow-R-Ball penetrated Level 2 armor, but was stopped by Level3A. And if you want to really fuck someone up with a handgun, I guess just use a 50 caliber.

Those bullets are too small. Get a .44 magnum or a .357 magnum or .38 special if you want a high velocity pistol.

[Mike in Denver]

I'm not an expert on guns, but you get lots more kinetic energy out of the .223 5.56mm NATO round than from ordinary factory off-the shelf 357 mag.

The numbers range a bit, but using fairly common values:

.223 5.56 NATO -- 55 grain 2600 fps produces 412.7 ft-lbs kinetic energy. (muzzle energy = 825 ft-lbs) [Note you can buy .223 5.56 NATO lots hotter than this, lots hotter]

.357 mag -- 158 grain 1300 fps produces 296.4 ft-lbs kinetic energy. (muzzle energy = 593 ft-lbs)

Of course results would vary with different bullet weights and muzzle velocity.

----

If you want to calculate your own values use this formula:

Kinetic Energy = 1/2 M * (V squared) --- Divide this by 450400
Muzzle energy is the same formula without the 1/2.

M = mass in grains; V = muzzle velocity in feet per sec.; 450400 is number of grains in a pound multiplied by gravitational constant 32. ft/(per sec / per sec)

I rounded off a lot.

Take home questions. Why do shooters use muzzle energy, rather than kinetic energy? Does muzzle energy have a meaning other than just being twice kinetic energy at the muzzle?

Enkidu

By the way. That Kel-Tec 223 looks like a great gun. I want one.

Oops. I just edited the formula. 450400 is (grains in a pound multiplied by the constant of gravity) * 2 (I had written 'divided')
Gosh! I'm surprised no one caught this. I think all the divide by 2, multiply by 2, complication goes away if you use the Metric system and calculate joules instead of ft-lbs.

[Mike in Denver]

Ha!!! I figured it out. Man, I'm surprised people haven't jumped in here. There is no difference in Kinetic Energy and Muzzle Energy. All the values above for Muzzle Energy are correct; ignore the values for Kinetic Energy, they are all half the correct values.

The formula for Kinetic Energy is simply K. E. = 1/2 MV^2. But since in the English system they use grains the factor to convert grains from weight to mass is 7000 * 32 ft/sec^2, to make the formula a little easier shooters moved the initial 1/2 into the conversion factor which makes it 450400 and dropped it from the initial formula, so they come up with... M. E. = MV^2/450400 with the 1/2 embedded in the grain from weight to mass conversion.

Wow!!

Enkidu