120mm vs 125mm

**Shek** · 23 Nov 09,, 20:00

Originally Posted by TopHatter

If your physics professor was here posting, instead of you, then that might mean something.

But right now it's you, a newcomer to this message board, that is posting.

Joe,
It'd still be irrelevant, because KE is not is what at issue here. It's about effects on target, of which KE plays a part, but is not sufficient.

**TopHatter** · 23 Nov 09,, 20:07

Originally Posted by Shek

Joe,
It'd still be irrelevant, because KE is not is what at issue here. It's about effects on target, of which KE plays a part, but is not sufficient.

I was trying to be polite, but as you said, he's fakin' the funk.

**Kommunist** · 23 Nov 09,, 20:08

Son, there are a lot of other parameters other than KE involved here. (Example - material of penetrator, think of firing a wood projectile with same weight and velocity as a DU projectile at an armor plate).

Take the cue, and let the pro's speak. They know what they are talking about, you don't.

**Officer of Engineers** · 23 Nov 09,, 20:08

Originally Posted by FNSNIPER

hey Guess what, My physics professor did not graduate in the US military academy, and Shek does not know quantum physics.

Don't even go there. You know crap all about quantum mechanics. I can bury you on that.

**tankie** · 23 Nov 09,, 20:14

oh dear , 10 9 8 7 6 5 4 ....

**Stitch** · 23 Nov 09,, 20:29

Originally Posted by tankie

oh dear , 10 9 8 7 6 5 4 ....

Pretty much (cue: Queen, "Another One Bites The Dust") . . . . . .

I'm going to go with the Reinmetall L/55 with an M829A3 round.

**roffelskates** · 23 Nov 09,, 20:30

Not to totally throw another wrench into this, but penetration is not just number of joules or foot pounds. There's also something called frontal desnsity to contend with. It's the difference between a hammer and an ice pick. A hammer that is not very dense will smash into something and release all it's energy, but have low penetration. An ice pick will penetrate through something releasing all it's energy to a single point and punching straight through. To gun folks, it's why a 5.7 round with less energy than a 45 ACP or 9mm can go through body armor while the latter cannot. So a larger round does not constitute greater penetration. A long thin and very dense object at high velocity can punch through more than something that is very large and not very dense going at a slower speed EVEN IF THAT OBJECT HAS GREATER ENERGY BY A FACTOR OF 2!

So energy isn't exactly the key factor to penetration.

**Shek** · 23 Nov 09,, 20:47

Originally Posted by roffelskates

Not to totally throw another wrench into this, but penetration is not just number of joules or foot pounds. There's also something called frontal desnsity to contend with. It's the difference between a hammer and an ice pick. A hammer that is not very dense will smash into something and release all it's energy, but have low penetration. An ice pick will penetrate through something releasing all it's energy to a single point and punching straight through. To gun folks, it's why a 5.7 round with less energy than a 45 ACP or 9mm can go through body armor while the latter cannot. So a larger round does not constitute greater penetration. A long thin and very dense object at high velocity can punch through more than something that is very large and not very dense going at a slower speed EVEN IF THAT OBJECT HAS GREATER ENERGY BY A FACTOR OF 2!

So energy isn't exactly the key factor to penetration.

You mean it isn't all about kinetic energy

)

**gunnut** · 23 Nov 09,, 20:49

Originally Posted by Shek

You mean it isn't all about kinetic energy

)

Sure it is. With enough brute force, anything is possible.

**Kommunist** · 23 Nov 09,, 20:51

Originally Posted by roffelskates

So energy isn't exactly the key factor to penetration.

Now the question is 'what kind of penetration are you talking about'?

)

**zraver** · 23 Nov 09,, 20:59

Originally Posted by FNSNIPER

I would say that the 125 mm round is better than the 120mm round, because of simple physics. The 125mm round has more kinetic energy upon impact, assuming that the places where they were fired form have the same muzzle velocities.

I will elaborate on the implications of kinetic energy later if need be.

Your an effing tard, do some research before showing the world how stupid you, are-principally be reading the this very thread.

125mm 2A46 family of guns and its Chinese clones use 2 piece ammunition. This limits projectile leangth and this has a direct bearing on projectile weight for KE rounds.

Weight is far more important for imparted energy than velocity.

an 8.3 kg projectile traveling at 1555m/s is far more energetic than a 4kg projectile traveling at 1750m/s

**~~FNSNIPER~~** · 23 Nov 09,, 21:07

Originally Posted by Shek

I majored in whoop a$$ with a 4.0 GPA in my two-course core physics sequence.

)

Now, I haven't seen the terminal ballistics of main gun rounds on the battlefield, which is why I haven't offered any opinion about the question at hand. I have, however, seen the effect of terminal ballistics of small arms ammunition on the battlefield, and having trained a rifle company on marksmanship (with my NCOs doing the heavy lifting), I do think I'm qualified to identify when folks are talking out of their a$$ and faking the funk, which you are.

BTW, please demonstrate how I "don't understand KE."

WTH is whoop a$$ doesn't fall under physics, neither does it fall under KE, last i checked. You dont seem to understan that to compute KE at any point in the trajectory all you need is the projectiles mass and the speed of an object at any point in its trajectory, which is effectively what i was saying all this while, while not disregarding the techinical factors that can affect such a calculation, whoop a$$ is not KE.

**Officer of Engineers** · 23 Nov 09,, 21:07

Z,

I think you mean momentum (mv), ie as in the Law of the Conservation of Momentum.

**Officer of Engineers** · 23 Nov 09,, 21:08

Originally Posted by FNSNIPER

WTH is whoop a$$ doesn't fall under physics, neither does it fall under KE, last i checked. You dont seem to understan that to compute KE at any point in the trajectory all you need is the projectiles mass and the speed of an object at any point in its trajectory, which is effectively what i was saying all this while, while not disregarding the techinical factors that can affect such a calculation, whoop a$$ is not KE.

Too dumb for this forum.