Somehow this looks like you are an apple-polisher.

Most articles of the NATO STANAG doesn't ban something. Several assault rifles use indigenous magazines, although there is a STANAG magazine, but most of them could be using a STANAG magazine. STANAG also doesn't limit special calibers to weapons or vehicles - there are British 120 mm rifled gun and two piece rounds and 120 mm smoothbore guns with single-piece ammunition. There are also different types of 105 mm guns and ammunition including recoiless one (which can't be used in tank guns of the L7 series).

There are some different points for STANAG, but they don't ban anything or prevent the usage of anything. Most of them are logistic reasons, some of them of tactical nature. Generally there is no point speaking for limiting the calibers which can be spotted on vehicles. Rifle ammunition like 7.62 x 51 mm or 5.56 x 45 mm is a standarized to improve the survivability of NATO soldiers; just imagine you as American would be fight side by side with a French company, you are surrounded by enemy forces - without STANAG, you wouldn't be able to continue fighting when your magazines are empty, since the French would have another catridge. If there wouldn't be any French causalities and they wouldn't have any other rifles, you would have to fight with a pistole. Since there is STANAG, you just would take some 5.56 x 45 mm rounds from them, and you could continue fighting.

Heavy vehicles, like infantry fighing vehicles or main battle tanks, aren't designed to reload on the battlefield. They must return to an ammunition depot or meet some kind of munition carrier vehicle. The tanks crew (or the crew of the IFV) wouldn't just open their hatches and reload their vehicles while being under fire.

well many belive the tiger sported the biggest gun would it be a myth the Joseph Stalin 40 tank has a 122 gun and the amercian t-26 (the m-26) mounted 90ml gun so why do so many think tiger is king i know the stalin was built in the war and saw limited action in berlin and the t-26 took part in crossing the rhine (by the way seen actual t-26 it in new hampshire)

in NATO members their are regulations that are followed such as stanrderd rifles round 7.62 by 51 or 5.56 by 45 or 120 main guns on many NATO MBTS.

Now one area little to no Stagnags appear present in NATOS IFVS for example the Amercian Bradley sports a 25 ml bushwacker well the British warrior sports a 30 ml Rarden gun and then we have Swedish CV 90 BOFORS 40ml main gun. then we have Germans, and French sport 20 ml guns.

why such wide range of calibers also if NATO adopted a STAGNAG what should they use?

my opnion is they should use 30 ml just right size and performace without sacrficing storage capciety

well the spansih made  a moive thats suppose to be representing a german army unit in bosian conflcit acting as peackeepers. if you watch the moive (its on youtube in bits) it uses spanish armored vehciles and spanish rifles along with odd assortment of Amercian weapons used by the Bosins like the m60 lmg. funy though they get the french rifle right the famas. they do sue the BMR-600

http://www.youtube.com/watch?v=bbkUvggIZ-w&translated=1

@ Burlington composite armour

I doubt that Burlington is exactly the same as the Chobham armour used in the Challenger 1. It is probably a little simpler, since the armour composition of Chobham was changed during the time. The M1 Abrams entered service some three years prior the Challenger 1, so it probably has a further developed varaint as the M1.

Edit: Here is some nice information about Burlington. Burligton was presented to a group of German soldiers and scientists (maybe as part of the FMBT programme?), the text claims that if Germany would incorporate Burlington (or another similar armour) into the Leopard 2, it would be first fielded in 1974. The Leo 2 entered service in 1979.

@ The usage of MEXAS in the Leopard 2 family

Take a look at the userlist on IDB-Deisenroth Engineering. Only some variants of the Leopard 2 use MEXAS. This models are operated/tested by Germany, Sweden, Greece, Spain and Switzerland. The Leopard 2 pictured there is the Leopard 2A6EX (as evaluated by Germany). Sweden has the Strv 122, which is the first production Leopard 2 which had increased hull protection (Denmark also use this upgrade, but the list is not up to date). Greece and Spain use a variant of the Leopard 2A6EX, therefore their Leopard 2s (E and HEL) are equipped with this applique armour.

The userlists also lacks some countries operating the Leopard 2A6 (e.g. the Netherlands & Portugal).

At the left there is a German Leopard 2A6. It is not equipped with MEXAS. The image on the right shows a Leopard 2A6EX in German camouflage pattern. Note the MEXAS applique armour layer on the hull and the increased roof protection.

Switzerland had developed an indigenious upgrade for their Pz 87 called "Werterhaltung". There the turret is reinforced with MEXAS-H.

Pz 87 equipped with 140 mm gun. Note the turret applique armour consisting of MEXAS.

Small composite armour compendium

This thread is including some information based on original image research.

Composite armour is used in most modern MBTs - there exist different types, different materials are used. There also are thousands of claims containing nothing but pure bullshit. Since I sometimes try to find some more information about the secret (or not secret) armours in the internet, I've found a lot of pictures of it. There are also some types of armour which can be considered to be a composite armour when using one definiton, but not with another.

BDD applique armour

The BDD applique armour package was developed and applied as part as an upgrade to T-55 and T-62 tanks, which were then called T-55M (or T-55AM) and T-62M. Some people claim that it is also used in the TR85M1 tank. This armour consistes of steel and a type of resin or plastic. A box (or at the turret front a "horseshoe") is made by welding further steel elements on the base armour. The inner space is then filled with thin, angled steel plates and the resin-like material.

The upgraded T-55AMs and T-62Ms are told to be better protected than some early T-72 models in some (but pretty large) areas.

1. Glacis applique armour
2. Turret applique "horseshoe" armour
3. A more detailed look at the turret armour
   

Leopard 1A1A1 applique armour

When the earlier production models of the Leopard 1 were upgraded they were quipped with some kind of newly developed applique armour, which is allegdly made by Blohm & Voss. Although most sources call this armour simple spaced armour, I think, because of it's working mechanism it shoud be called a simple type of composite armour.

The armour consists of perforated steel plates coated in some type of rubber/lexan. This armour is mounted on shock-adsorber bolts on the thin base armour. When hit, the armour takes some use of the NERA effect. According to some posts in other forums, this armour should be protective against the BR-412, the main armour piercing 100 mm tank round of the earlier stages of the Cold War, which was later replaced by more effective APDS and APFSDS rounds.

1. A Leopard 1A1A4 without applique armour. The shock-adsorbers in the frontal area are larger, to increase frontal protection.
   
2. A closer look at a armour module showing the perforations in the steel plate.

Leopard 1A3 and 1A4 armour

The Leopard 1A3 and the later Leopard 1A4 tanks were eqipped with a more sophisticated welded turret. The turret incorporated a new type of armour. While most self-published sources simply claim that it would be protected by a simple type of spaced armour, it is as cited on Wikipedia, according to G. van Zelm & B. A. Fonck (two Dutch authors) a type of composite armour. It is told to be consisting of two spaced steel plates (the outer steel plate is high hardened) and a plastic filling (Polystyrol) between them. The German wikipedia article about composite armour may give a hint why it is often claimed to be spaced armour. The article differentiates between three generations of "Schottpanzerung" - the first genertation consists of spaced steel layers, the second has a plastic filling between them, the third generation is defined by the usage of rubber for making use of the NERA-effect.

The Leopard 1A3 frontal turret armour is told to offer twice as much protection as the former upgraded turret on the earlier models.

1. A close-up view on the welding seams of a Leopard 1A3 turret
2. The same image with some information superimposed - Note: the steel layers seem to be only 40 to 50 mm thick, but they are sloped vertically and horizontally.

Leopard 2 turret armour

Not much is known about the armour used in the Leopard 2 family. It is a multi-layered composite armour with Chobham-style ceramic matrix layer(s). But there are some nice images about the welding of the turret (i.e. the Greek company licence-producing them leaked), so the armour thickness is known. According to a Russian webpage (btvt.narod) the armour has a maximum thickness of 70 cm, while the German protal WaffenHQ claims that the actual thickness is 80 cm, as measured by German soliders & conscripts. Claimed materials inlcude tungsten, rubber, aluminum, titan, ceramic tiles, steel and plastic.

1. A turret being welded. Note: the thick "boxes" will be filled with composite armour, while the rear includes two blow-out compartments
2. Another turret being welded
3. An Austrian Leopard 2A4 with "composite boxes" superimposed

Leopard 2A5 applique armour, the "Keilpanzerung"

Several Leopard 2s were upgraded following the "Mannheimer configuration" which was made by most of the Leopard 2-using countries. The most obvious change between the original slab-sided turret and the upgraded one is the installation of wedge-shaped armour modules on the front.

Contrary to what is claimed on TankNutDave.com this armour is not MEXAS, it is a type of armour developed by KMW. MEXAS is used in the Leopard 2A6EX, Strv 122, Leopard 2E, Leopard 2A5DK and Leopard 2HEL - it is not applid to the turret front, but to the frontal hull armour (and maybe it is used as roof armour).

The armour module consists of three layers of unknown material, which are told to be high-hardened. Between them is rubber, at least according to some forum posts in different forums. The armour module is using an unique working mechanism. It doesn't work like steel armour or ceramic armour (i.e. as passive non-spaced armour), instead it is told to be tearing and shearing the KE-penetrator (HEAT warheads will only be detonated prior reaching the main armour), which alledgly reduces impact energy of the penetrator by some 30 %.

A Greek Leopard 2 turret is told have been shot with as much as 30 APFSDS rounds, only one of them penetrated the armour through the former position of the EMES-15 gunner sight. Later this weak spot in the turret armour was fixed on all Leopard 2A5/6s.

1. The multi-layered wedge-shaped add-on armour module. The walls are thin, but the effect is big
   
2. A Leopard 2A5 turret without frontal armour modules and gun; the former position of the EMES-15 was reinforced. Note: the base armour is not perforated armour
   

M1 Abrams turret armour

While there is not much known about the armour of the Leopard 2, only a little more is known about the composite armour used in the M1 tank. At first, a Chobham-derivate known as Burlington was used, later depleted uranium was used to improve the protection.

In some forums like the TankNet, images of knocked out M1 Abrams were posted - the side armour of the turret seems to consists of steel plates, maybe some kind of plastic was also used, but there are no ceramic tiles visible! Maybe they were removed or destroyed when the steel armour was destroyed.

1. Multiple steel layers
2. The steel layers seem to be fixed on some kind of coil spring, the turret armour seems to be very thin

Merkava glacis armour

The Merkava tank family is based on a unique design - e.g. they mount the engine in the front. This is allegdly improving the protection, but I believe the engine is mounted in the front, because of the rear mounted exit; the Merkavas were designed to carry some infantrymen with them for engaging enemy anti-tank troops.

During watching some documentaries on YouTube, I found a video recording of the "ten greatest tanks of history" on discovery channel. The Merkava was ranked fourth in this docu. During one interview, the "engine hatch", i.e. the glacis armour was opened, to film the engine.The glacis armour seems to consist of three layers of differnt and unkown matierals. Maybe Israel used a similar technique as the Russian used in there T-64s and T-72s (some T-72s were captured during some wars).

1. A bad quality screenshot, sharpened to show some more detail; there are three different coloured layers. The image was sharpened to increase the visibilty.
   
2. Here the glacis armour is overlaid by lines showing the borders of the layers; all layers seem to have the same thickness.

T-55 Enigma applique armour

The "Enigma", modified T-54 and T-55, were used by Iraq during the Gulf and the Iraq wars. Large metal "boxes" were welded on the turret and glacis. The same type of armour was also used as side-skirts. Although there might be different versions, the modules inlcude some type of spaced composite armour.

The armour seems to consists of three types of material: Steel, rubber and some other material (a kind of plastic?).

1. The turret of an Enigma tank. One armour module is fold up.
2. A close-up view of the armour module; a metal section is cut out, three materials are visible: a white/grey material, a darker layer of rubber and a brown material.

T-72 armour

The T-72 is one of the earliest tanks using composite armour. The composition of this armour may have changed, but the thickness and the materials used in most versions are largely known. The first models used simple composite armour made of two steel layers and plastic or other materials (some models incorporated Kwartz).

1. The cast steel turret of the T-72B (it actually matches with an desription of the T-72M armour, maybe my translator software made an error) includes a "pocket" which is filled with a composite armour array
2. The armour module which is filled in the "pocket". It consists of 20 composite layers, each layer consits of 30 mm steel, 6 mm rubber and a 3 mm steel. 22 mm space is between each composite layer.
3. This image shows the glacis armour of the PT-91M without ERA. It is exactly the same as the original T-72M which were reinforced with a 16 mm (32 mm LOS) steel layer.

To be expanded!