SSK 6.5 MPC: Best Assault Rifle Cartridge for 21st Century Warfare?

**cato** · 17 May 07,, 02:35

Leib,
I've not heard of a 5.56 round that will penetrate a Level IV plate, but I think that it will probably be the construction of the round rather than it's caliber that allows that penetration to take place. No armor remains impervious for long. A nicked femoral artery will cause a GSW victim to go hypovolemic in a few minutes without the application of direct pressure or a tourniquete. He will still have time to empty his magazine at your sorry ass (although, admittedly, his aim probably wont be the best). It is also an impossible shot to make in combat (from what I hear, not trying to claim anything different!). It seems that it is almost impossible to hit an extremety during combat situations, so hitting the medial aspect of the limb would be that much more difficult. Also, when the artery is severed, at least proximal from the pelvic cavitry, the hugely powerful quadricep will contract and form a natural tourniquete (at least for a while). It is a nicked femoral artery that is truly dangerous, as it is not severed, and won't creep up the leg and be pressured by that big hunk of quad. Again,m my info is second hand, and readily available on the web, but it seems that if you are facing an armored opponant, controlled pairs COM, than failure drill to the head or pelvic girdle solves the problem.
Thanks,
Cato

**gunnut** · 17 May 07,, 03:35

I have not heard of the 77 gr. 5.56mm bullet. All I have are 55 gr. and 63 gr. stuff.

What rifling do you need for the 77 gr.? How about barrel length? Is there an optimal length for 77 gr.?

**Swift Sword** · 17 May 07,, 04:07

Originally Posted by Stan187

Problem with the M4 is that the round doesn't have enough velocity to tumble past 50 meters. Long barrel are needed for that with the same round, to extend stopping power at further ranges.

Hi Stan,

I am thinking that the issue here might actually be related to the rifling pitch.

Seems to me that the "tumbling" effect is a function of yaw and yaw is, externally speaking, variable with rifling pitch if all other things are being equal.

I am happy with the Armalite pattern weapons with barrels as short as 10 inches if I have advanced billing as to the twist and round in question and will expect good 250-300 yard performance as a rule.

Regards,

William

**cato** · 17 May 07,, 04:10

Hey Gunnut,
From what I understand the 77gr matchpoints are only issued to the SDMs. They use basically a souped up M-16A4, with standard rifling, and a 20"bbl.
Sucks to be a gun guy in Kali, no?
Thanks

**Swift Sword** · 17 May 07,, 04:13

Originally Posted by leib10

Besides, a shot to the femoral artery would end the fight pretty quick.

Leib,

Femoral artery is wrapped in a small piece of meat.

I am personally inclined to shoot at the biggest piece of meat I can hit.

Regards,

William

**Swift Sword** · 17 May 07,, 04:36

Originally Posted by bonehead

Just lamenting that whenever all the conditions are not nearly perfect the .556 fails as with that round the margin of error is tiny. After three decades we are still trying to overcome the rounds shortcomings. Enough is enough already. Screw the beancounters and politics. Lets get a round to the soldiers that will let them do their job most effectively. Tha adaptation to the .556 was a mistake. It is time to admit that mistake and move on.

Bonehead,

'Tis an old argument.

Greener's magnum opus of a century past has a table of "incredible shrinking service rifle bore diameters" that is illuminating.

Hackley's study of U.S. ammunition development details attempts to improve .30 caliber and .45 caliber ammunition performance with various "Manstopper" bullets because they came up short.

I am not sure where the truth actually lies but critics and detractors abound for what many consider to be the solution to contemporary problems: "bigger is better" and their criticism is a two or more Century phenomenon.

I guess it pretty much boils down to this: regardless of weapon (they are actually darned near equal for all intents and purpose) hit what you want BANG! BANG! BANG! ***Click***throw it in the gutter and go get another.

AK, Armalite, G3, M1, Springfield, SPIW, various SIG products, Mauser du jour, etc., etc: does it really matter? I told my people that it was what was between their ears and not their hands that decided the day.

Of course, we considered the Browning P35 a 200 yard perimeter weapon and the suppressed .22LR a 300 yard weapon

Regards,

William

**leib10** · 17 May 07,, 05:42

Originally Posted by Swift Sword

Leib,

Femoral artery is wrapped in a small piece of meat.

I am personally inclined to shoot at the biggest piece of meat I can hit.

Regards,

William

Naturally. For unarmored targets.

Say, for instance, a man broke into my house, wearing body armor. My USP is loaded with .40 S&W 135 grain Pow'rball rounds. These would be devastating against soft targets, but I would not bet my life on the rounds penetrating body armor. So that leaves either a headshot, a shot to the extremities, or a groin shot.

**Stan187** · 17 May 07,, 20:57

William, what type of twist would you need for such a short barrel as a 10" in order to get that good performance out to 250-300 yards like you say? The standard one is 1/9 I believe...

**leib10** · 17 May 07,, 23:21

Depends. If you are using SS109 ammunition, 1:7 is the standard twist. For M193, it's 1:9.

Although both will fire the other ammunition, optimal performance is achieved only when the ammo designed for the twist is used.

For instance, my DPMS AP4 carbine has a 1-9 twist, being optimized for the older M193 round. However, it will shoot SS109 just fine, although with not quite the same degree in accuracy.

AFAIK the SS109 is a more stable and accurate round. However, I could be wrong, so correct me if I am.

The HK 416's cold hammer-forged barrel gives increased performance out of the shorter barrels when compared to standard barrels.

**gunnut** · 18 May 07,, 06:44

Originally Posted by cato

Hey Gunnut,
From what I understand the 77gr matchpoints are only issued to the SDMs. They use basically a souped up M-16A4, with standard rifling, and a 20"bbl.
Sucks to be a gun guy in Kali, no?
Thanks

Sigh...you said it.

I don't have any cool toys here. Mini-14 is probably the best we can have.

**bonehead** · 18 May 07,, 09:30

Never fear Gunnut. I am sure the Cali contingent of legislators, from the federal level down to your local goverment, is doing everything within their power to save you from yourself and take that "evil mini" from you as well.

**leib10** · 18 May 07,, 15:22

I couldn't live in PDRK.

God bless Texas and its gun laws.

**FOG3** · 22 May 07,, 21:16

Originally Posted by gunnut

Sigh...you said it.

I don't have any cool toys here. Mini-14 is probably the best we can have.

Can't get to Free Zona, huh?

**omon** · 22 May 07,, 22:17

Originally Posted by gunnut

Sigh...you said it.

I don't have any cool toys here. Mini-14 is probably the best we can have.

i feel you, here in nyc we got the same thing, no ak,s ar,s or mp,s along with many other weapons.
damn i miss LI i could have as many ak,s as i wanted, or anything else for that matter.