Modern tank cannons - smooth vs rifled

[33Vortex]

See my above post. 120MM gun not 122mm.

Also the Soviets last tank that had a rifled barrel was the T-54/55. That had a 100mm rifled main gun. The T-64/72/80/90 ALL use a 125mm smooth bore main gun, the T-62 used a 115mm smooth bore main gun, so I don't know what tanks they had that they were carrying extra barrels into battle. Also changing the main gun tube on a tank is NOT something the crew can do on their own, and is NOT something you stop and do in the middle of a battle. Also the most commonly used tank by the Soviets in Afghanistan was the T-64. The Soviets supplied old T-55's to Afghan Army units. Desert Storm the Iraqi's were using T-62's T-72's for the most part. Some units were equipped with the old T-55's, but I never saw an Iraqi tank with a spare barrel strapped on the side and I saw ALOT of blown up tanks over there.

Perhaps he was thinking of the BMP, BRDM or some other armored vehicle? That's a completely different story.

[Maverick]

The twin military experts fishu and shrimp have been conspiring again to print the "real" truth as they see it. 

Replacing a main gun tube is not field level maintenance. It is never done in the field nor at front line areas. Not only is it a piece of equipment weighing more than a "couple pounds" it has to be integrated with the gun system. It's not like swapping a barrel on a machine gun which is an area weapon BTW, not an accurate point weapon.

Anti personnel weapons on the M1 are the MG's that were installed in and on it. They work fine. The main target of a tank is other armor, not troops in the battle field, that is why armor is not employed separately but as a combined arms unit with infantry. Infantry protects the tanks from the infantry and the tanks protect the infantry from other tanks and armored vehicles. They also add additional direct fire to the enemy positions and troops. HEAT rounds work as explosive rounds since they create overpressure and frags as well as an armor penetration device. Armor is a shock weapon system not a primary anti infantry system.

[Bodhi]

The most reliable automotive systems seem to come from Japan - their cars can be seen on the roads far longer than any western car.

[Mustaine]

There's a "new" thread about this same topic, posting the same video

http://bbs.hitechcreations.com/smf/index.php/topic,244641.0.html

Guess it needs the same "you are dumb and ignorant guys who like to suckle Jeremy Clarkson" smack down as this one.

[Motherland]

lmao, it's not about that. That's just one little comment in the beginning of the video. Not the subject of the thread...

[bj229r]

Beat me to it. The 120mm A30 cannon on Challenger 2 can fire HESH rounds which have a longer range than its APFSDS round. The HESH round is also better when you want to blow stuff like buildings up rather than turn the contents of an armoured vehicle to mush.

To be honest, you could argue the relative merits of Challenger 2, Leopard 2, Le Clerk and Abrams all day and not reach consensus - they're all good, evenly matched tanks. However, in the interests of adding a bit of nationalistic jingoism and keeping the thread interesting , I'll say this:

1. The only thing to have ever killed a Challenger is err, another Challenger. This is relatively unique in the British army. Traditionally it is the US Air Force that destroys our armoured vehicles.

2. The Abrams, like the M60 before it, originally used a British Gun. It now uses a Geman gun. It also uses armour developed by the British. Which begs the question - isn't the M1 really just a European tank with a gas-guzzling turbine engine stuck in the back?

 

Harleys have German pistons (at least they did 10 years ago).......I bet the Brit gun leaked oil.....

[Elfie]

Both, rifled and smooth bore guns, fire loads of different ammo types, from APFSDS, HEAT, HEFRAG, etc, all the way to guided missiles.

Iirc, only smooth bore guns fire guided missiles.

[MrRiplEy[H]]

The twin military experts fishu and shrimp have been conspiring again to print the "real" truth as they see it. 

Replacing a main gun tube is not field level maintenance. It is never done in the field nor at front line areas. Not only is it a piece of equipment weighing more than a "couple pounds" it has to be integrated with the gun system. It's not like swapping a barrel on a machine gun which is an area weapon BTW, not an accurate point weapon.

Anti personnel weapons on the M1 are the MG's that were installed in and on it. They work fine. The main target of a tank is other armor, not troops in the battle field, that is why armor is not employed separately but as a combined arms unit with infantry. Infantry protects the tanks from the infantry and the tanks protect the infantry from other tanks and armored vehicles. They also add additional direct fire to the enemy positions and troops. HEAT rounds work as explosive rounds since they create overpressure and frags as well as an armor penetration device. Armor is a shock weapon system not a primary anti infantry system.

T80 Maintenance and repair

High manufacturing quality and design peculiarities of the tank have made the tank easy in maintenance and repair:

    * maintainability of the power pack has been achieved due to the optimal building block design. Time required for the replacement of the tank power pack in the field constitutes only 3 hours;
    * the application of the quick disconnecting connection gun tube with its breech allows to replace the gun tube in the field conditions without dismantling the gun from the tank turret;
    * the fire control system and the armament control complex have the built - in control and collimation system;
    * engine air intake device design on T-80U tank ensures air dustiness de-crease at its intake into the engine in more than 10 times what in combination with the unique system of automatic dust removal from the engine setting elements guarantees engine reliable work at any air dustiness without maintenance. This level of air cleaning was proved by the tests in the deserts of Middle Asia and desert Tarr;
    * fuel and oil systems' elements are made of stainless steel what ensures their high corrosion durability;
    * T-80U tank is fueled by the closed stream through one filling throat besides during the filling up process fuel undergoes additional cleaning coming through the special filter. This makes maintenance much easier and excludes dust and moisture getting inside the fuel tanks;
    * auxiliary power pack allows to carry out storage batteries maintenance and charging, all systems and complexes functioning check and maintenance without starting the main engine what is especially important while conducting the works indoors.

[Angus]

That is not an M1, and the T's of any brand had a bad day against the Challenger.
But....is it the weapon, or is it the man behind it?

p.s. The smooth bore can fire longer rounds, so that means heavier for the same width of barrel. With a shell equally short, the rifled barrel will be more accurate. There is a reason for your rifle being....rifled 

[Elfie]

With a shell equally short, the rifled barrel will be more accurate.

Unless you are firing Sabot rounds, then the smooth bore will be more accurate.  The fins on Sabot rounds stabilize the round in flight so the rifling isn't needed, or wanted even.

There is a reason for your rifle being....rifled

The rifling imparts a spin to the projectile which stabilizes it in flight and makes it more accurate.

[Chalenge]

The most reliable automotive systems seem to come from Japan - their cars can be seen on the roads far longer than any western car. Mercedes used to be the innovator of automotive systems, but I haven't seen many innovations recently.

I think there will always be amazing examples of machines that outlive their designed lifespan. I have an Uncle that still owns the first car he bought brand new off a car lot. I think any Japanese car that came in contact with it would look like a crumpled soda can since its made of steel. Gas hog? Of course thats the American way! We should not have to model our lives after mamby-pamby girly boys. 

[FrodeMk3]

Unless you are firing Sabot rounds, then the smooth bore will be more accurate.  The fins on Sabot rounds stabilize the round in flight so the rifling isn't needed, or wanted even.

The rifling imparts a spin to the projectile which stabilizes it in flight and makes it more accurate.

If you fellas are really interested in AFV Main Gun and armor comparisons, check this out:http://members.tripod.com/collinsj/protect.htm

It's pretty up to date, and it has some interesting Data.

[Cthulhu]

Unless you are firing Sabot rounds, then the smooth bore will be more accurate.  The fins on Sabot rounds stabilize the round in flight so the rifling isn't needed, or wanted even.

The rifling imparts a spin to the projectile which stabilizes it in flight and makes it more accurate.

Another VERY important reason why modern MBTs don't use rifled barrels is that the preferred weapon to kill other tanks is what's called a "long-rod penetrator". These weapons, like the Abram's "Silver Bullet", have large L/D values (long and narrow) which concentrate a lot of energy over a very small area. (sectional density to you guys who shoot or reload). These long darts can't be spin-stabilized worth a damn because they wobble badly if spun at high rpm's. They have to be fin-stabilized and encased in sabots.

In addition, HEAT rounds really don't like being spun either, the rotation having a negative effect on the forming of the copper slug and the blast shape. The French found this out with their old AMX-30 and actually mounted the hollow charge on bearings within their HEAT rounds to minimize spin.
 
These are probably the main reasons that smooth-bores are used. Although less barrel wear is definitely a plus.


Oh, and Clarkson is always taking shots at Americans. I just laugh it off. Top Gear is great.

[FrodeMk3]

See my above post. 120MM gun not 122mm.

Also the Soviets last tank that had a rifled barrel was the T-54/55. That had a 100mm rifled main gun. The T-64/72/80/90 ALL use a 125mm smooth bore main gun, the T-62 used a 115mm smooth bore main gun, so I don't know what tanks they had that they were carrying extra barrels into battle. Also changing the main gun tube on a tank is NOT something the crew can do on their own, and is NOT something you stop and do in the middle of a battle. Also the most commonly used tank by the Soviets in Afghanistan was the T-64. The Soviets supplied old T-55's to Afghan Army units. Desert Storm the Iraqi's were using T-62's T-72's for the most part. Some units were equipped with the old T-55's, but I never saw an Iraqi tank with a spare barrel strapped on the side and I saw ALOT of blown up tanks over there.

Hornet, the T-64, even with it's long service life, has only ever seen combat in Chechnya. The Primary tank used in Afghanistan was the T-62.

During the Soviet war in Afghanistan, the T-62 was a primary tank used by the Soviet army.[16] The Soviets used tanks pretty much in the same way as the US Army did in Vietnam, with many tanks in fire support bases. Towards the end of the war T-62Ms appeared in large numbers. This modernized variant of T-62 had the BDD appliqué armour package specially designed to defeat shaped charges (for example RPGs). Many T-62s fell victim to Mujahideen attacks and, especially, antitank landmines, as did many Soviet AFVs sent there. Many also fell into the hands of the Afghan Mujahideen after being left behind by withdrawing Soviet forces. Those vehicles as well as derelict ones restored to working order are now used Afghan National Army. Afghan army operates 170 T-62, T-62M and T-62M1 tanks.[11]

The Russian army has also used both T-62s and T-62Ms in combat in Chechnya. The T-62M is still being used for counterterrorism operations in this region.[12]

http://en.wikipedia.org/wiki/T-62

[indy007]

That is not an M1, and the T's of any brand had a bad day against the Challenger.
But....is it the weapon, or is it the man behind it?

I think it's obvious, the tank is not the asset at all, the crew is. You can build a new tank far faster than you can re-train a good crew. Pretty much all MBTs have the same basic features... Challenger, Leopard 2A6, M1A2, Merkava 4, T-90... long gun, heavy armor, high speed, good optics & sensors, good comms. Now except for the T-90, which I don't think has seen combat yet, does anybody know of a case of any of these tanks ever losing crew members? I know some M1s and Merkavas have been disabled, but I haven't read of any crew losses. I do remember one story of a M1 driver having his tank wrecked with a multiple 105mm shell IED, but they carved into the tank 6 hours later and the guy was still in his position without a scratch, just really bored.