This'll be a copy & paste job from the multitude of other threads on how overpowered .50s and Hispanos are relative to the Panzer IV.
Apparently some people still believe that P47 and P51 "tank busters" strafed the road in front of tanks to get bullets to bounce up and through the bottom hull (which was armored, by the way), so I'll start off with that.
I'll then move to armor data and penetration tables if I can still find them.
Firstly, the 'I saw History Channel, it said P51s and P47s killed tanks by bouncing bullets off the road into the tank's belly!"
"Most tanks destroyed by strafing were the result of engine fire or damage....also have read about p-51's and jugs killing tiger tanks by firing into roadway (rear attack) and igniting fuel with ricochets off pavement." (sorry Humble, yours was the first one I saw)
(another good one) "I watched the P-47 show on the history channel. Watched several gun cams of p-47's blowing the living crap out of tanks with their 8 .50 cals. So, don't tell me its not possible. Unless you're claiming they faked the footage? When they learned to bounce their round from underneath, they were REALLY meat on a hook. "
Reply "Gaining better angles through ricochets defeats velocity and deforms rounds thereby reducing their effectiveness at perforating armour. The pilots note themselves that they could not be sure."
"I've often wondered about reports of "bouncing bullets off the road into the bellies of tanks to set them afire"-- as the bellies of these tanks are still too much for such light projectiles to handle, particularly after losing much energy by striking the road surface first, and then likely tumbling or yawing severely before strking the belly armor."
"During the 1944-5 NW Europe operations, an Operational Research team from the RAF trekked around the battlefields as soon as the enemy had departed, examining German equipment and assessing the reasons for its destruction.
Their conclusions were that very few tanks were destroyed by any form of air attack. On average, they found perhaps one-tenth the number that the fighter-bomber units were claiming. Those which were destroyed in this way were generally hit by rockets or bombs.
This is discussed at length in Ian Gooderson's "Air Power at the Battlefront: Allied Close Air Support in Europe 1939-45" which is required reading for anyone interested in this subject.
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>
The MG 131 AP could similarly manage between 7mm and 3mm
The MG 151 15mm AP (non-Hartkern) from 19mm to 12mm
The MG 151 15mm Hartkern 24mm to 12mm
The MG 151 20mm AP between 12mm and 8mm
The 20mm MG-FF AP between 9mm and 6mm "
All of these guns COULD (in theory) penetrate a tanks upper decking and turret. In practice? Well, the Mg151 isn't effective at all, and the MG-FF would be a complete waste of time. The Hispano can kill a Panzer IV with ease (and you don't have to be firing at 200 yards to do it, either), and the .50 can disable a Panzer IV easily (and from what I understand kill it as well). Furthermore, the "high" end of the scale is a 60 degree dive. At 300 yards. From 30 degrees, none of the guns could penetrate. I know for a fact that I don't strafe tanks at a 60 degree angle or at 300 yards... I typically break off before getting to 300 yards, but the rounds still go through and kill the tank.
It is easy to test, go to the DA with a friend, have him up a Panzer and strafe him. Make sure you film it, so you can look at exactly how shallow your approach really was. The Panzer IV has been broken for 2+ years, it would be very nice to have this looked into.
