I think you answered your own question in your last sentence of the OP. The AT gun was made obsolete not only because of better armor but better weapon systems. Here is a link where you can get an mpeg of a javlen in action. http://www.geocities.com/txmac66/Downloads.html
For LinoleumInnocence:
Tank: A combat vehicle with full armored protection to all small-arms (rifle, pistol, etc) and machine gun fire, also with an anti-vehicle weapon system. (frequently, but not necessarily, an anti-tank system)
Current US tank: M1 Abrams, in several upgraded flavors
APC: Armored personnel carrier. A combat vehicle with some or full armored protection against weaponry up to heavy machine guns, designed to carry mechanized infantry on a battlefield (albeit not necessarily right into combat) Weaponry usually consists of no more than a machine gun. Relatively inexpensive, basic vehicle.
Current US APC: M113 (not sure if it’s still used in mech.inf role by:)
IFV (subset of APC): Infantry fighting vehicle. An APC with heavier weaponry. Often an autocannon or low-velocity cannon, quite often with anti-tank guided missiles as well. Generally carries less troops than plain APCs, always cost more. These are designed to keep up with tanks, bring troops straight into combat, even into a nuclear/biological/chemical battlefield, and fully support them during combat.
Current US IFV: M2 Bradley
AFV: Armored Fighting Vehicle. Encompasses all of the above
Cavalry: A specialized combat arm trained and used for quick and constant maneuver and all tasks based on such: largely scouting and striking at an enemy’s flanks, rear areas and/or logistics. Used to be synonymous with horses, which is why the proper term these days is:
Amoured Cavalry: Cavalry made of AFVs
Mechanised Infantry: Infantry specially trained for the mechanized role. This includes things like how to fight from an APC or IFV and proper methods to support armored vehicles (like tanks) in areas where they’re vulnerable.
Some Corrections and Addendums:
Phoenix Dragon: the Fire Control System of the M-1 series MBT will calculate a ballistic solution to 4000 meters with a relatively high degree of accuracy. The Laser Range Finder, which inputs directly to the Fire Control System, will provide ranges accurate to 10 meter increments out to 8,000 meters.
In operation, superior gunners have been know to induce some “Kentucky Windage” and hit targets at 5,000 meters and above. I’m sure that American tankers are not unique in doing this; our foreign counterparts with sufficient experience and ability undoubtedly yield similar results.
A knowledge of ballistics, and knowing the range and the gradiation of your vehicle’s target reticle will allow a quick, dexterous tank gunner to adjust fire accordingly and achieve target hits with consistency.
I’ve said before, and will do so here again, that quite often the tank’s gunner is more of a limiting factor than the hardware.
LinoleumInnocence, Mekhazzio: the M-113 is no longer used in U.S. Forces in a direct-combat role, but rather as an armored, general purpose forward-deployed support vehicle, quite often by combat medics and first echelon follow-on maintenance assets, and in variations as a FIre Support Team Vehicle (FIST-V) for calling and directing artillery fire.
But at that range, the round is in flight long enough that hitting a moving target starts becoming questionable and requires more work of the gunner, like manually compensating for the ranging error from the distance traveled by the target between lasing and impact and requiring much more accurate tracking than at, say, 1200m. The more of the ‘human factor’ is introduced into the equation, the less chance of a hit, and if a target knows you’re firing at it and tries to evade…well, just figure in how far a vehicle can deviate from its course during the time of flight. It starts to add up pretty fast, and past a certain point, it makes the inherent accuracy of the system almost irrelevant, as it’s merely human brain (gunner) vs human brain (driver)
3.2km is probably a pretty good ballpark for effective range against ‘the average opponent’.
If a target is kind enough to stand still for you, you could theoretically hit it out to maximum visual range…but I doubt we’ll find many other armies that are stupid enough, especially after that big basic tactics lesson in 1991, to use tanks as pillboxes, especially in the flat terrain needed to accomodate such a shot.
You could consider the Bradley a Light Antitank gun (or a light tank.) Here is a quote from http://www.fas.org/man/dod-101/sys/land/m2.htm.
“The Bradley’s main armament is the M242 25mm “Bushmaster” Chain Gun, manufactured by McDonnell Douglas. The M242 has a single barrel with an integrated dual-feed mechanism and remote ammunition selection. Either armor piercing (AP) or high explosive (HE) ammunition may be selected with the flick of a switch. The Gunner may select from single or multiple shot modes. The standard rate of fire is 200 rounds per minute, and has a range of 2,000 meters (depending on the ammunition used). A wide range of ammunition has been developed for this weapon, making it capable of defeating the majority of armored vehicles it is likely to encounter, up to and including some main battle tanks”
This gun would probably eat through any armor if given the time. (Esp rear shots) If nothing else it would make the opposing crew button up. Given the chance the bradley would fire the tow instead. Unfortantly the Bradley has to stop to fire these.
These are one hell of a lot better then m113 they replaced.
A few Danish Leopard 1 tank crews in Bosnia learned long-range shooting the hard way - if you’re on one mountain and the enemy is on another, there’s little room for maneuvering into range. Of course, they weren’t fighting real soldiers but a bunch of militiamen who somewhat belatedly came to realize that “UN” did not mean “This tank will not shoot back”.
S. Norman
The 155 mm howitzer is still in limited use as an anti-tank gun. With the Copperhead round M-109 crews can engage armored targets up 15 or so miles away. Granted some poor observer has to paint the target with a laser.
I have no idea how effective this is against top of the line tanks. The effects I’ve seen observing the impact against old M-60s were impressive. When the guidance fins pop out it makes a nice eerie whistling noise. Sounds cool from the gun line.
The Copperhead will still kill any modern MBT it manages to hit. There isn’t much you can do on any practical MBT to protect against ‘bombs from above’
well its why MBTs are on their way out infantry are the backbones of armies and more so …
but then as a tank commander you could zig zag across the battle field rather than drive straight or be supported by infantry first who sweep the area for blokes who designate the artillery / A-10s
You’re mixing your definitions. An anti-tank gun is a direct fire weapon, that is, it fires straight at a target within line of sight, A howitzer is an indirect fire weapon, firing at targets outside of their immediate line of sight, that can be used for both high and low trajectory shots. All artillery has some small utility in the direct fire role, but it’s a desperation move at best, to attempt to defend against an overrun where enemies have penetrated behind the lines. It’s not something that anyone wants to have to use.
As for artillery’s capability to kill tanks, yeah, a 155mm HE shell will, if it can hit, pretty much annihilate any vehicle through brute force. Getting that hit through normal bombardment is highly unlikely, barring the use of guided rounds like Copperhead (which require a lot more work to set up a shot for, on top of being much more expensive) – the typical “artillery versus tanks” ordnance is DPICM, dual-purpose improved cluster munition. Instead of one large shell with lots of explosive, this is a casing that airbursts over the target area and spits out lots of little shaped charges that float down. This way one shot covers a lot more area, wihle still being capable of defeating the top armor of almost every AFV in existence. It doesn’t have the one-shot-one-kill reliability of Copperhad, but it does potentially have a several-shots-many-kills capability, when used on massed targets. Nasty stuff.
Most military types would have an apoplectic fit to hear you say that 
The Bradley’s 25mm autocannon has zero hope of killing a contemporary tank…it’s made for attacking other IFVs and similar thin-skinned vehicles. Tank armor can’t really be “worn down” (it can, but not in the way you’re thinking of, so somewhat irrelevant) – it’s an all or nothing proposition. You either penetrate the armor and do damage (usually lethal) or you don’t penetrate and the tank doesn’t care. There are a few external gadgets that could be damaged (like the primary gunsight) but largely, if you can’t beat the armor, you’re just screwed.
The Bradley’s only hope against tanks is the TOW missile, which is there ostensibly for ‘self-defense’ purposes. Seeing as how the Bradley is a thin-skinned vehicle carrying at least eight people, and ATGMs generally cannot go head to head with tank cannons and win, it’s not SUPPOSED to fight other tanks, even though, in some special situations it reliably can. This is actually a matter of some debate amongst the military, as some people believe an IFV shouldn’t even -have- missiles, since it might encourage the crew to use it as a “light tank”. Personally I think that’s bunk…an IFV without ATGMs in the presence of enemy tanks is called a “target”.