Wow!, Bradley's knocking out T-72s?

[Boroda]

Originally posted by Mini D
Miko, I think you are still confusing issues.

The effective range of artillery is much greater than that of a cannon.  The need for the large guns is still there.  Nobody is laying claim to a 25mm round taking out a T-72 before the T-72 was in range to fire.

And, once again, I think you are underestimating the capability of a depleted uranium tipped round.

MiniD

MiniD, JFYI: Miko served in Soviet Army as a tank gunner/commander, on a T-72.

My "opinions" are mostly theoretical, and I have some knowledge on how modern weapons work, but I didn't complete my studies. Had to quit in 92 when my College administration made it obligatory to attend lectures, so I had to choose - job or studies.

Now let me tell a story about a T-72 turret, that I promised

Disclaimer: I repeat it as I heard it from my professor, "selling it for the same price I bought it".

T-72 turret has 2 layers of armour with a layer of sand between them.

How it happened: in early-70s they tried to make turret lighter and OTOH capable to withstand more damage. So they designed it with 2 layers of armour, empty space inside. Turrets are moulded into sand forms. Then they are mechanicaly shaped, I mean the "precise" surfaces like the bottom ("pogon") where it is mounted to the hull. So they made 10 new experimental turrets, and 2 of them were out of order: they couldn't get the send out of the interior space. When the turrets were brought to the shooting range, some engineed said: "Well, why not try to shoot at the bad turrets?". And they turned out to withstand damage much better then "empty" ones. So now all T-72 turrets are filled with sand

This story was told us to explain that things as armour penetration are almost unpredictable under conditions that are far from ideal. And usually almost anything makes penetration smaller.

Again: DU isn't magic. It has it's limitations. I bet good ol' RPG-7 will do more damage. Even from short distance.

Did you hear about a company of T-70s that "killed" a Tiger in 1943? They were armed by 20mm ShVAKs. I think it's pretty obvious that they simply destroyed the suspension, broke periscopes and gun sights and jammed the turret. No way to penetrate the armour.

[miko2d]

Mini D: Miko.. you keep bringing up the larger artillery as reasons the 25mm is not effective.

 No. Whoever sold you that mind-reading device has certainly fooled you. Brought the larger anti-tank armament as an indication that western designers armed their main ground-based tank-killer - main battle tank - not with four 25mm cannons but with a single 125 mm one.
 They must have had some reasons about the general efficiency of those. Which says nothing about short-range efficiency of 25mm DU rounds in some situations. So you may want to thrain your mind-reader on them.

Once again, its about range.  How much farther can an M-1 fire than a T-72?  Which has the range advantage?

 I have no idea - and pretty sure very few people really do. If youc ompare the caliber, weight, muzzle velocity and ballistic properties of the M-1 and T-72 DU penetrators, you may find them very close.
 What most "armchair tankers" forget is that in all past and curent conflicts:

1. US tanks fired while moving on stationary enemy tanks - it makes huge difference whether the target is moving or standing still since even at the incredible penetrator speeds a tank can move few of lengths in the seconds it takes the projectle to arrive.

2. US tanks usually had initiative and fired first - which means they had time to set up that crucial first shot after which subsequent shots are easy since the distance is automatically substracted.

3. There was never indication that the enemy tanks ever had DU penetrators. If it's true, then they had to rely on the HE or HEAP rounds that are starting at about three times as slow and worse downrange. Those rounds have much higher trajectory, making correct range estimate way more crucial. They arrive few seconds too late which make lead estimation way more crucial - basically impossible. They are trully 1/4 of a range compared to a DU penetrator. When they actually hit the target, HE causes little damage while HEAP is easily defeated by reactive and composite armor.

4. The Iraqi T-72 apparently have clumsy inaccurate parallax rangefinders despite good laser ones available for the last 20-25 years.

5. The quality of american crews is incomparably better.

 So yes, against a basically unarmed stationary target that cannot shoot back for the lack of the proper ammo, you can say that the M-1 range is far greater.


 I am sure that if american crews were using T-72 tanks with the proper ammo against entrenched M-1s manned by iraqis, the outcome would have been much the same.

Once again... I'm not arguing that the Bradly is an effective anti-tank weapon.  Just that it can penetrate a tank's armor with the 25mm.  Of course, in order for it to get into range, it has to rely on one hell of a lot of missing by the tank or an inept tank crew.

 And I am not arguing otherwise. Anyway, since you are so interested in that, could you look up the real specks for those ammo - muzzle velocity, velocity at 1000 yards, how much armor it's supposed to penetrate, etc.
 In Russia such info is probably classified but I would not be surprised if it were public in the US.

 miko

[Suave]

Doesn't anybody remember the footage of 20mm vulcans fluff'n up abandoned t72s in 91 ?

[miko2d]

Boroda: T-72 turret has 2 layers of armour with a layer of sand between them.

 The technical term is "ceramic"...

 That kind of multi-layered variable-material armor, possiby even withs some cavities, was intended to defeat the HEAP rounds that used a narrow stream of molten metal formed by specially-shaped charge. Along with the reactive armor it was quite effective - which made armaments side concentrate back on the true and tried "throw a heavy piece of metall really fast" method.

 miko

[Boroda]

Miko, from what I read in Western sources, D-81 (2A36) cannon rounds loose it's velocity too fast. So at short distances it penetrates up to 1.5 times more then Rheinmetall 120mm. At about 1km enemy cannon is told to be better. They say it's because our rounds are lighter. The muzzle velocity is 1800m/s vs. 1600m/s for enemy cannon.

 When I studied we didn't have such charts, mostly because Western 120mm was quite new when I was in college. And even if we were told that range/velocity charts - they were in our "secret notebooks".  I only have a xerox of my "secret notebook" from first year, on "energy-cintaining materials" course...

Interesting that now both Rheinmetall and Soviet designers are developing larger caliber tank cannons, 150 and 152mm. AFAIR they are rifled, but I may be mistaken. Looks like they are relying on an impact impulse now, not on velocity...

[miko2d]

Boroda:  The muzzle velocity is 1800m/s vs. 1600m/s for enemy cannon.

 I had a distinct impression that it was above 2100 m/s - at least 40% more energy than at 1800 m/s. Of course that was what the officers told us - I have no way to know.

 Fast light rounds have flatter trajectory. Soviet tanks were supposed to close fast in attack in overwhelming numbers and western ones to be defending and capable of taking a lot of punishment before being disabled.

 miko

[ccvi]

Originally posted by GScholz
Muzzle velosity and projectile weight are the key factors. The US 120mm and Russian 125mm APFSDSDU rounds have insanelly high muzzle velosities. Much more than can be generated by a 25mm or 30mm weapon. The speed of which the projectile can be accelerated down the barrel is determined by the projectile's base area, just like the pistons in an engine; wider bore=more HP, longer stroke=more tourqe.

Muzzel velocity does not matter. If at all it's impact velocity
Mass does matter, because to increase it at the same shape of the bullet it requires a larger density of mass, which is good for penetration.
Increasing the diameter does not really help. You can put more energy in, but it doesn't increase speed, because at larger diameter the bullet is also considerably more heavy. A certain diameter is required to build bullets that are stable enough at the required length. If there was an infinitly tough material the cheapest bullet to penetrate thick armor would look like a weapon the first humans on earth invented

[miko2d]

The russian round actually has additional propellant charge stored behind it's guide ring. That's where it gets a lot of extra energy. The ring is kept together by a copper band that seals the bore and the ring is split into 3 sectors, IIRC, and has special holes drilled into it in such way that it flies apart once it leaves the barrel.

 I am not at sure that the fins are wide enough to stabilise the projectile in the barrel.

 miko

[Charon]

Urban Myth or surprising fact?

There was an old Army "fact" that if you happened to be in a buttoned-up M-113 (I assume it would apply to any light-skinned fighting vehicle or APC) and a sabot round passed through it the occupants would be sucked out through the exit hole. I knew a guy who even knew some guys that tried it on the range once with a fox or coyote

Doesn't seem likely to me, but stranger things...

So, truth or myth

Charon

[AKIron]

Debate it all you want.

Bradleys: 5
T-72s: 0

[Mathman]

Originally posted by ccvi
Muzzel velocity does not matter. If at all it's impact velocity
Mass does matter, because to increase it at the same shape of the bullet it requires a larger density of mass, which is good for penetration.
Increasing the diameter does not really help. You can put more energy in, but it doesn't increase speed, because at larger diameter the bullet is also considerably more heavy. A certain diameter is required to build bullets that are stable enough at the required length. If there was an infinitly tough material the cheapest bullet to penetrate thick armor would look like a weapon the first humans on earth invented

Velocity is more important than mass.  The simple Kenetic energy equation shows this:  E = 1/2 mv^2.  What that says is that if you double the mass, you double the kenetic energy.  If you double the velocity, you quadruple the kenetic energy.

[Golfer]

I watched as Captain Lyle was interviewed on CNN by Walter Rodgers following the engagement, and the Bradley's fired at the Turrets of the T72 and used their 25mm cannon for the tank kills.  This interview wasnt that much longer after they patched up an iraqi officer who had been laying in a berm thought to be dead for upwards of five hours.  CNN has been doing their part helping out.  This iraqi officer was given primary first aid by a CNN security officer who was retired SAS, also they have on reporter who is a Neurosurgeon and has performed two operations (not current info, last i saw him on the television was 2 days ago).

[Hobodog]

Remember even if it doesnt penetrate the energy goes somewhere. That somewhere is often through the amror where the inside flakes of into shards and can richochet at super high speeds through the inside of the tank ripping everything including electronics and flesh to shreds. Its like shooting a beebee gun into a barrel. It will go ping-ping-ping-ping several times before dropping down.

[StSanta]

Does someone have a hart showing armor penetration for DU rounds fired for instance from the Avenger cannon and the 55mm Bradley one?

MiniD, I wasn't confusing the terms, but I wasn't very clear either . Blame it on the flu (hopefully not SARS lol).
The 30mm Avenger cannon round not only has a higher ROF, it also has a higher initial muzzle velocity IIRC - courtesy of the airspeed of the plane that boosts it slightly, as well as a higher mass.

And I wasn't talking single round penetration but rather general weapons effectiveness. With the Avengers very high ROF, higher mass and veloity, it is a much more potent weapon. Add then to the fact that the rounds impact at a better angle and you have overall a much better weapon.

As it has been said, there's a difference between destroying and disabling a tank 25mm DU rounds could very well do signifiant damage to the rear of a T-72, but fired on the frontal armor at very shallow range penetration seem unlikely. The huge 125mm gun on an M1 is not solely for range - penetration at all angles is also what it was designed to do.

But I wanna see some numbers before I trust claims made on a battlefield. If we were to go by what the fighting sides claim, we'll end up with more shot down planes than were actually built .

Wonder what the gunners of the T-72's were up to. Sure, I'd focus on the Abrams too. OTOH, knowing that the Bradleys fall easier and have TOW missiles, I wouldn't hesitate in choosing a Bradley at short range rather than an M1 at long. And as a commander I'd know the propaganda value of images showing US hardware blowing up in small pieces. But in the end I'd do the smart thing rather than die; pop a stolen smoke grenade inside the vehicle and exit. With a little luck my commander will think I got hit and not shoot me, and with a little more I'll have enough time to leg it outta the way from a soon exploding and burning tank.

So far, the M1s and Challenger II tanks have performed their job admirably. What other tanks are there of that generation? I know the Israelis have one they're mighty proud of and claim is better than the M1, and I know the Germans have a new Leopold (sp?). Also, what's the latest Russian tank called, and anyone got any specs on it?

[Dinger]

my understanding, based on hearsay, is that the T-72 main gun has a higher max range, but the Abrams main gun has a higher effective range.  The T-72 can shoot farther, but the abrams can hit farther out.  As Miko says, it's not simply ballistics.