Man, that is an awesome shot. I think it shows .... a spitfire knocking out a tank from 600 yards at about a 45 degree angle.
But.... but... that isn't possible...
Well, it shouldn't be, but I'm sick of going round and round about it for 3 years now. I'll just post the data, you all be the judge. GVs have been a side-show joke for as long as I've been playing this game.
Gun data
(Per Tony Williams unless otherwise noted)
First, the weapons and their ammunition. The standard British Hispano loadout from around 1942 onwards was an equal mix of SAP/I and HE/I. The SAP/I could penetrate no more than about 20mm armour, at short range given a favourable (ie head-on) hit. There was AP ammo (the USA made some) which pushed the performance up to over 30mm, and the British also developed a tungsten-cored shot capable of 45-65mm penetration, but this was never used.
Given proper AP rounds, the Hispano would be significantly better, but AFAIK the US M75 AP shot wasn't used in Europe. The RAF loaded only HEI and SAPI according to my info, and the SAPI was about the same as the .50 M8 in AP performance.
The .50 M2 AP or M8 API were also capable of penetrating around 20mm maximum, in the most favourable conditions at up to 200m.
""A .50 caliber API round is easily capable of penetrating armor up to at least 19mm of face hardened plate ... at 100 meters." (Per
http://www.rovingguns.com/lunatic/wwII_gun_analysis/ )
Panzer IV Armor
Front Turret: 50/11
Front Upper Hull: 50 or 50+30/10
Front Lower Hull: 50 or 50+30/12
Side Turret: 30/26
Side Upper Hull: 30/0
Side Lower Hull: 30/0
Rear Turret: 30/10
Rear Upper Hull: 20/12
Rear Lower Hull: 20/9
Turret Top / Bottom: 10/83
Upper Hull Top / Bottom: 12/85
Lower Hull Top / Bottom: 10/90
Gun Mantlet: 50/0
Encyclopedia of German Tanks of World War II lists the H turret top armor as being 15mm at 84 - 90 degrees. Superstructure is 12mm at 85 - 90 degrees and the hull is 10mm at 90 degrees.
"The USAAF/RAF gun armour penetration figures I quoted before were generally measured at about 200m, and involved striking at 90 degrees (or 0 degrees, depending on which convention you favour). Penetration fell off increasingly rapidly as the striking angle became less direct, although the rate of fall-off depended on the design of the projectile; there is no formula which will give you this. Yaw was also a factor (ie the degree to which the bullet wasn't travelling point-first - particularly a problem at short range before the bullet stabilises in flight, and can also be caused by hitting anything en route to the target). The following extract about the .50" from my next book illustrates this:
"The official requirement for the M2 AP was to penetrate 22 mm steel at 183 m (the M8 API was expected to match this figure at 92 m). The striking angle is not specified but is assumed to be 90º. Official US tables for the M2 show penetration at 300 m as follows: 21 mm / 90º, 13 mm / 60º and 5 mm / 30º. These measurements were to the USN criterion which called for 50% of shots to penetrate. British tests at 183 m determined that the M2 would penetrate 21 mm at 0º angle of yaw (i.e. the bullet was flying perfectly straight) but this dropped to 15 mm with only 10º of yaw (such as might be caused by passing through an aircraft’s skin before hitting the armour). Taking the effects of striking angle and fuselage structures into account, it seems likely that the practical penetration of either the M2 or M8 was in the region of 10-15 mm in normal circumstances."
The important part here is
Taking the effects of striking angle and fuselage structures into account, it seems likely that the practical penetration of either the M2 or M8 was in the region of 10-15 mm in normal circumstances."
Another post
"Realistically, an attack on the roof or decking of a tank is not going to be made at better than 60 degrees, with 30 degrees being more likely. Furthermore, it's not going to be at very short range. So let's take 300m range and strikes at 60-30 degrees as typical.
As I posted before, the .50" M2 AP could penetrate between 13mm and 5mm in these circumstances (with the smaller figure being more likely). < My NOTE: Hispano has similar results>