Ya, I know this is long range hunting, but I have always wondered how the 120 mm SMOOTH BORE main gun is so accurate. We talk about rate of twist for rounds and so on for which weight bullet... to no end, yet the military is getting supurb accuracy out of a smooth bore gun. I am assuming that the rounds are saboted rounds with stablizers which cause the round to spin, but I'm not sure. Also, I am pretty sure that the British Challenger tank has a 120 mm rifled gun, is there a difference in the accuracy between the two??? Just got me thinking.....
M1A2 Abrams Accuracy
- Thread starter britz
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generaldoeboy
Active Member
- Joined
- Jun 8, 2008
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are you sure the m1a2 barrel is a smooth bore?? im pretty sure its rifled. However the Abrams sights are incredible it will shoot a laser onto a target and gather target speed, wind drift, barometric pressure, altitude, humidity etc in a fraction of a second and send them to the gunner and he then pulls the trigger and away it goes. Of course he has to have a baseline information that his ammo was tested on. The Abrams also uses the sabot round.
LewisH
Well-Known Member
Here's the dope on this gun:
M1 ABRAMS ARMAMENT
The main armament is the 120mm M256 smoothbore gun, developed by Rheinmetall Waffe Munition GmbH of Germany. The 120mm gun fires the following ammunition: the M865 TPCSDS-T and M831 TP-T training rounds, the M8300 HEAT-MP-T and the M829 APFSDS-T which includes a depleted uranium penetrator. Textron Systems provides the Cadillac Gage gun turret drive stabilisation system.
M1 ABRAMS ARMAMENT
The main armament is the 120mm M256 smoothbore gun, developed by Rheinmetall Waffe Munition GmbH of Germany. The 120mm gun fires the following ammunition: the M865 TPCSDS-T and M831 TP-T training rounds, the M8300 HEAT-MP-T and the M829 APFSDS-T which includes a depleted uranium penetrator. Textron Systems provides the Cadillac Gage gun turret drive stabilisation system.
Ammo for the 120MM Smooth Bore of the Abrams
The L44 can fire a variety of shells, and while the majority are primarily designed for the anti-tank role, most of them can also successfully engage other types of targets as well. The L44 is presently rated to fire the following types of ammunition:
Armour-Piercing Fin-Stabilized Discarding Sabot (APFSDS): A round that uses a dart made of depleted uranium (used by the U.S. Army and others, but not by the German Bundeswehr) or tungsten to pierce the armor of enemy tanks using kinetic energy. The U.S. version, the M829A1 gained fame during Operation Desert Storm for its lethality against Iraqi tanks, leading some tank crews to give it the nickname "silver bullet".
High-Explosive Anti-Tank (HEAT): A shell with a shaped charge warhead.
Multi-Purpose Anti-Tank (MPAT): A HEAT round with an added proximity fuze to allow it to engage slow, low-flying aircraft such as helicopters.
Canister: A shell filled with tungsten shot that acts like a giant shotgun shell for use against buildings, dug-in infantry fighting positions, and thin-skinned vehicles.
High-Explosive Fin-Stabilized (HE-FS): A shell with a proximity fuze for use against low-flying aircraft, and against tanks by air bursts against rear and top armor.
Source of the info here,
Rheinmetall 120 mm gun - Wikipedia, the free encyclopedia
The L44 can fire a variety of shells, and while the majority are primarily designed for the anti-tank role, most of them can also successfully engage other types of targets as well. The L44 is presently rated to fire the following types of ammunition:
Armour-Piercing Fin-Stabilized Discarding Sabot (APFSDS): A round that uses a dart made of depleted uranium (used by the U.S. Army and others, but not by the German Bundeswehr) or tungsten to pierce the armor of enemy tanks using kinetic energy. The U.S. version, the M829A1 gained fame during Operation Desert Storm for its lethality against Iraqi tanks, leading some tank crews to give it the nickname "silver bullet".
High-Explosive Anti-Tank (HEAT): A shell with a shaped charge warhead.
Multi-Purpose Anti-Tank (MPAT): A HEAT round with an added proximity fuze to allow it to engage slow, low-flying aircraft such as helicopters.
Canister: A shell filled with tungsten shot that acts like a giant shotgun shell for use against buildings, dug-in infantry fighting positions, and thin-skinned vehicles.
High-Explosive Fin-Stabilized (HE-FS): A shell with a proximity fuze for use against low-flying aircraft, and against tanks by air bursts against rear and top armor.
Source of the info here,
Rheinmetall 120 mm gun - Wikipedia, the free encyclopedia
royinidaho
Well-Known Member
Son in law is an E9 Cannon Cocker w/the Idaho National Guard. Says they have a GPS guided projectile. He says it's pretty much spot on and has fins that do the guiding.
I'm figgering the 375 Cal projectile is the smallest cal that I can rig to be GPS guided. However, the electronics will take up core space resulting in less weight but the increased rotation rate will increase the terminal performance.
I'm figgering the 375 Cal projectile is the smallest cal that I can rig to be GPS guided. However, the electronics will take up core space resulting in less weight but the increased rotation rate will increase the terminal performance.
MSU Marksman
Well-Known Member
I thought the British Challenger was the only tank that had a rifled barrel.
Challenger 2 tank - Wikipedia, the free encyclopedia
I would also guess that "accuracy" is measured a little different for them. As long as they hit "minute of tank", I think it's considered accurate. I don't think I've ever heard of tanks shooting for groups, but that would be a neat match to watch.
Plus, whats the B.C. of a 120mm projectile? 500?
Challenger 2 tank - Wikipedia, the free encyclopedia
I would also guess that "accuracy" is measured a little different for them. As long as they hit "minute of tank", I think it's considered accurate. I don't think I've ever heard of tanks shooting for groups, but that would be a neat match to watch.
Plus, whats the B.C. of a 120mm projectile? 500?
I guess your right that the Challenger 2 is a rare breed in that it has a rifled barrel. But it is pretty amaizing that any of these tanks are capeable of hitting a 8 foot target at 1 mile, 2 miles, or even 2.5 miles on every shot! That is something to write home about in my opinion.
MSU Marksman
Well-Known Member
After watching the special on the History channel last night, it was noted that smoothbore barrels are used to reduce pressures, and increase a seal around the base of the projectile. Also, rifling is not needed for projectiles this large because the projectiles themselves have fins built in. The current sabot round for the 120mm tank gun is fired at 4200 FPS and has a range of 7.5 miles. It looked more like a 20mm arrow in a 120mm sabot jacket.
msalm
Well-Known Member
The first versions of the M1 tank, and M1IP had a 105mm rifled barrel. They converted all of them over to the 120mm smoothbore some time ago, not sure when, but I've been on them both. I've worked on a few of them at times replacing turret components and pulled a few gun tubes for services...they are impressive and the fire control equipment is pretty awesome. The reticle takes many different things into account to include movement, range, temp, etc... and then corrects for the shot. The gunner can just use a center hold, much like a click-and-shoot, only its done for him at the click of a button.
