P-47 Movie (26 mb)

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It can be classified as a weak HMG yes, but it wasnt weak ! It could easely penetrate the thin skin of an airplane and most of whatever behind it. The 7.92mm S.m.K.H. projectile could penetrate 20mm of 90 degree armor at 550m :!:

The Normal Vo for the 7.92mm machineguns were 890m/s.
 

The 7.92mm S.m.K.H. could penetrate 30 mm of homogenous plate at point-blank range at 90 degrees (perpendicular). At 100 meters it could penetrate 13mm, and at 500 meters it could penetrate 8 mm. This ammo made up only about 1-2% of 7.92 mm production in 1941 through March 1942, when production ceased. By Feb. 1943 all stocks had been depleted.

Besides, I don't believe this ammo was ever used for aircraft guns.

=S=

Lunatic
 
The SmK(H), meaning Spitzer mit Kern ( hart) = pointed with core (hard) this was the best armor piercing version of the 7,9mm cartrigde. The projectile had a length of only 28.2mm, weighed 12.5 g and contained a tungsten core that was 22.5 mm long. The propellant gunpowder of the shell was increased to 3.6 g.

Production of this ammunition type ceased in March 1942 because of an acute shortage of tungsten; still, SmK(H) cartridges continued to be issued to the troops and some to the Luftwaffe as late as February 1943.
The initial speed was about 830 meter per second

[/b]
 
My understanding from a brief research of this ammo is that it was for the MG34 only, and that it ruined out a barrel in something like 200 rounds, and that it was not used in the MG17.

=S=

Lunatic
 
Lunatic the S.m.K.H. round penetrated 20mm of steel at exactly 550m

You want a reference with that one ?
 
Soren said:
Lunatic the S.m.K.H. round penetrated 20mm of steel at exactly 550m

You want a reference with that one ?
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Sure. But if you have one, it's wrong! The figure at 500 meters was 8mm penetration at 90 degrees.


Source: http://www.wwiivehicles.com/html/germany/guns.html

Panzer Truppen The Complete Guide to the Creation and Combat Employment of Germany's Tank Force 1933-1942, Thomas L. Jentz, 1996

Panzer Truppen The Complete Guide to the Creation and Combat Employment of Germany's Tank Force 1943-1945, Thomas L. Jentz, 1996

Even with an initial velocity of 890 m/s, the round has poor sectional density. Lets calculatate it. The round weighs ~12.5 grams and has a radius of ~4mm. Area of a circle = Pie * radius squared.

3.14 x 4 x 4 = 50.24 square mm.
12.5 grams / 50.24 square mm = ~0.25 g/mm squared.

Lets compare this 13mm API-T, which has similar ballistic shape. Weight is 38.5 grams and radius is 6.5 mm.

3.14 x 6.5 x 6.5 = 132.7 square mm.
38.5 grams / 132.7 square mm = ~0.29 g/mm squared

So as you can see, the sectional density of the 7.92 mm S.m.K.H. round is ~12% less than the 13 mm API round, which means it will have inferior ballistcs. It's also not a tracer round, meaning it will have even more inferior ballistics. It's also starting at 890 m/s which means it will slow dow faster at the beginning because of the higher mach speed.

By 500 meters the 13 mm API-T was down from an initial velocty of 710 m/s to 368 m/s, a loss of 48% of its initial velocity. It is clear the 7.92 mm S.m.K.H round would have at least 15% worse velocity retention.

There is no way that the 7.92 mm S.m.K.H could penetrate any 20mm of steel at 500 meters. Its velocity is down around 400 m/s at that range! And by 550 meters it's going sub-sonic!

=S=

Lunatic
 
Sure. But if you have one, it's wrong! The figure at 500 meters was 8mm penetration at 90 degrees.
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No it isnt, yours is ! My primary reference is the book 'MG34-MG42 Universal machineguns' and varius other books about military surplus ammunition, plus experience in firing many of the rounds myself.

The website you quoted is notourisly inaccurate ! Just look at some of the other penetration stats !




What ? A tracer-round isnt more accurate than a normal round

The most accurate round you can get is a Boat-tail round, wich the Germans invented btw

Also im not comparing the 7.92mm round with the 13x64Bmm round.


Let me remind you that the 7.62x63mm 1950 AP round will penetrate 9mm of steel at 500m, and the 7.92x57mm S.m.K.H. round has been proven superior to the 30.06 AP round every time a test with the two were carried out. As a matter of fact i can testify to that, as i own alot of German WW2 surplus ammunition !

At our farm we had a 15mm thick metal plate hanging on a pole, and from about 400m away we would practice shoot after it. Whenever we used 1950's 7.62x63mm AP rounds, we found that they were unable to penetrate the plate, however our 7.92mm S.m.K.H. rounds penetrated every time, and they were 'clean' penetrations ! (I was impressed !)

Quote:

Between 80 and 90 % of all 7,9mm ammunition produced was of the 7,9 sS (sS for schweres Spitzgeschoss = "heavy pointed bullet") type; the complete cartridge weighed 27g, it was 80.6 mm long and contained 2.7g of gunpowder; the projectile weighed 12.8 g and was 35mm long. When fired from a MG34 or MG42 (as well as from the other rifles using the cartridge) it had a typical V0 of 755 m/s. The regular sS projectile had the following penetration performance: 85cm of dry pine wood at 100m, 65cm at 400m, 45cm at 800m and 10cm at 1,800m; 10mm of iron at 300m, 7mm at 550m; 5mm of steel at 100m; 3mm at 600m.
The second most used type was the SmK (Spitzgeschoss mit Kern = "pointed bullet with core") bullet that measured 37.2mm, weighed 11.5 g and contained a hardened steel core (about 8% of all produced 7.9mm rounds).
Another type was the SmK L'spur (L'spur = Leuchtspur = "bright trace" = "tracer") bullet that was the previous type combined with a tracer that burned for 800 to 900 m (a little less numerous than the SmK). In the picture at right a soldier is seen preparing a 7.92mm ammunition belt for a machine gun (presumably adding tracers at every seventh round).
The lS (leichtes Spitzgeschoss = "light pointed bullet") which had an aluminum core and therefore weighed only 5.5g which resulted in a higher speed of V0 = 925 m/s but of course also in a shortened total range (the bullet was used mainly in the air defense role; about 4-7% of the total production), the lS-L'Spur which with a length of 37.2mm and a weight of 6.1g was again the tracer version of the lS (less than 1% of total production).
A version produced mainly for use with the MG 17 as aircraft armament was the so-called V-Patrone which had an increased powder charge that increased the V0 by 15%. This ammunition type was available with the PmK projectile ("Phosphor mit Stahlkern" = "phosphor with steel core") or with the B ("Beobachtung" = "Observation") projectile contained a little phosphor and exploded upon impact, the latter ammunition type was also known as the B-Patrone and was used as an incendiary round; both types are not counted in the 7,9mm production.

The final and most interesting bullet type was the SmK(H). The H stood for Hartkern (hardened core), this was the armor piercing version of the 7,9mm Infanteriepatrone. The projectile had a length of only 28.2mm, weighed 12.5 g and contained a tungsten core that was 22.5 mm long. The propellant gunpowder of the shell was increased to 3.6 g. The bullet had a penetration power of 20mm of plain steel at a range of 500m (90° impact angle). However, production of this ammunition type ceased in March 1942 because of an acute shortage of tungsten; still, SmK(H) cartridges continued to be issued to the troops as late as February 1943. while it was still inproduction, this ammo type accounted for 1 to 2 % of the production of 7,9mm Infanteriepatronen.

When the machine guns used the normal sS ammunition they achieved an armor penetration of up to 10mm and more at close ranges
 
Soren said:
The P-47's highest top speed was 433mph, the Bf109K-4 451mph

Also the P-47 would bleed energy much quicker And the Bf109K-4 would turn inside a P-47 any day at any speed

I'd go for the Bf109K-4 !!
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I thought the fastest speed for a Jug was 450mph.

The 109 has heavy controls at high speeds, so saying it can turn inside the Jug at any speed is a little bit too mutch...And if you are really in trouble, point the nose down and kiss that 109 goodbye!!!
 
I thought the fastest speed for a Jug was 450mph.
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Not according to its specifications.

The 109 has heavy controls at high speeds, so saying it can turn inside the Jug at any speed is a little bit too mutch...
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First of all that was worse with early 109's such as the E series, K-4 less so.

And if you are really in trouble, point the nose down and kiss that 109 goodbye!!!
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No arguement there The P-47 was like stone when diving, and I've never heard that anything could follow it in a dive !
 

You have no experiance firing this round at 8/10th inch thick armor plates. If your reference book gives this figure, it is wrong. It is so far out of the bounds of reason it boarders on ridiculous.

Soren said:
The website you quoted is notourisly inaccurate ! Just look at some of the other penetration stats !
Click to expand...

Other sources give similar figures. I'll find some more for you if you like. Meantime, what page of your book is that figure quoted on? Can you scan or photo it and provide it?


All other things being equal a tracer round looses velocity slower than a non-tracer round. The gas being emitted by the tracer hole at the rear of the round fills in some of the vacuum behind the round and reduces parasitic drag.

Soren said:
The most accurate round you can get is a Boat-tail round, wich the Germans invented btw

Also im not comparing the 7.92mm round with the 13x64Bmm round.
Click to expand...

I only compared these two rounds as an example because they have similar ballistic shape.


At our farm we had a 15mm thick metal plate hanging on a pole, and from about 400m away we would practice shoot after it. Whenever we used 1950's 7.62x63mm AP rounds, we found that they were unable to penetrate the plate, however our 7.92mm S.m.K.H. rounds penetrated every time, and they were 'clean' penetrations ! (I was impressed !)[/quote]

Practically no 7.92mm S.m.K.H rounds survived WWII, so how did some kids on a farm get hold of them to try them out? The few that exist are collectors items with collectors item price tags. And, what rifel would you have fired them from? They are known to ruin the barrel of a MG34 in just 200 rounds!

Besides, what does it matter. This ammo was never used on aircraft guns.

=S=

Lunatic
 
You have no experiance firing this round at 8/10th inch thick armor plates. If your reference book gives this figure, it is wrong. It is so far out of the bounds of reason it boarders on ridiculous.
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As a matter of fact yes i have ! Although it wasnt armor plates, it was a metal plate ! (So the quality of the plate i ca't garantee !


Other sources give similar figures. I'll find some more for you if you like. Meantime, what page of your book is that figure quoted on? Can you scan or photo it and provide it?
Click to expand...

Yes please provide ! And no i don't own a scanner.

Practically no 7.92mm S.m.K.H rounds survived WWII, so how did some kids on a farm get hold of them to try them out?
Click to expand...

Kids ?? And yes some did survive the war !

The few that exist are collectors items with collectors item price tags. And, what rifel would you have fired them from? They are known to ruin the barrel of a MG34 in just 200 rounds!
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As a matter of fact it was done by accident with a K98k, and the bolt got stuck after the first round ! So we couldnt fire anymore than one round with that rifle. However even the normal S.m.K. round could penetrate the plate, at atleast 200m

Besides, what does it matter. This ammo was never used on aircraft guns.
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The S.m.K. was ! And so was the V round !
 
It is so far out of the bounds of reason it boarders on ridiculous.
Click to expand...

No it damn well isnt !

Even the 'weak' 7.62 NATO AP round can take on a plate of much better quality !
 

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Soren,

Having done some further research on the issue, it appears the source doc you used is highly suspect. Probably a mistake in the translation.

Consider this. The Patrone 318 SmKH-Rs- L'spur 7.92 mm anti-tank round, fired from an anti-tank rifle, had an initial velocity of over 1200 m/s and was able to penetrate 25 mm of mild steel at 300 meters at Zero degrees (i.e. perpendicular).

Other soruces state penetration of 13-14 mm @ 100 meters for the 7.92 mm SmKH round (fired at ~890 m/s).

If the 20mm @ 500 meter figure were correct it would mean that the Hispano 20mm AP and SAP rounds would have been able to easily defeat Panther armor, which we know was not true.

=S=

Lunatic
 

Ummm.... that plate is of what quality? Besides, it's only about 10mm thick and we have no range figure for the hit.

=S=

Lunatic
 
RG_Lunatic said:
Ummm.... that plate is of what quality? Besides, it's only about 10mm thick and we have no range figure for the hit.

=S=

Lunatic
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Its of alot better quality than the metal plate we practice shot against, thats for sure And im sure the one on the picture is more like 15mm in thickness.

About the fault in translation, and the ability to penetrate I've done some research myself.

What i found was apparantly the German tested their AP round against different types of "Metal" plates, such as 'Steel' and just plain 'Iron' ! The results were very different from against 'Steel' to against 'Iron'.

The regular sS projectile had the following penetration performance: 10mm of iron at 300m, 7mm at 550m; 5mm of steel at 100m; 3mm at 600m.

For the normal Ss bullet: 10mm of 'Iron' at 300m, and 7mm at 550m. 5mm of steel at 100m and 3mm at 600m. A normal drop in penetration ability from 100-600m = 40%
 

I think you are overestimating the thickness of the plate. Look at the round sitting right next to it lying on it's side. The base of the bullet (where it meets the casing) is 7.62mm. The plate is no where near twice that thickness!

I would suspect more drop in penetration between 100m and 600m. The round will slow down more than 40%, and penetration is based on something in between momentum and kinetic energy.

Anyway, I hope you see my point. If a 12.5 gram tungsten core AP round could have penetrated 20 mm of armor at 500 meters, a 130 gram AP round would have easily defeated any armor on the battlefield.

BTW, I have some experiance shooting 30-06 ammo at various things myself. When I was a kid we used to shoot up an old abandon dairy farm with a variety of guns, including M1's, Springfields, Enfields, and SKS's. We got a lot of ammo for free from one of the guys brothers who was a quartermaster at Camp Pendelton.

What I remember is that the 30-06 AP rounds would go all the way through an 8" railway tie. There was an old wrecked Chevy truck we shot up too. A 30-06 ball round would go through the hood, through the firewall, through the dashbord (metal), through the seat, through the back of the cab, through the front of the bed, and severely dent the far side of the bed. An AP round would continue out through the back of the bed.

The transmission was missing from the truck (I think someone had helped themselves to it) and the engine with no heads was laying on the ground near the truck. The 30-06 would also penetrate the engine block from some angles, the AP would pentrate the block and get into a cylinder. However, even the AP round only made a gouge in the flywheel, which is made of decent quality hard steel almost 3/4 of an inch thick.

We typically fired from ranges of about 80 meters (guestimate), using a convieniently placed concrete water feeder to sight from (and protect from possible ricochets).

=S=

Lunatic
 
I think you are overestimating the thickness of the plate. Look at the round sitting right next to it lying on it's side. The base of the bullet (where it meets the casing) is 7.62mm. The plate is no where near twice that thickness!
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No it isnt twice the thickness of the7.62mm round (15.22mm), but its somewhere around 12-12.5mm I would guess.

I would suspect more drop in penetration between 100m and 600m. The round will slow down more than 40%, and penetration is based on something in between momentum and kinetic energy.
Click to expand...

Well thats actually a very normal drop, its about the same as with a 30.06 round.

Anyway, I hope you see my point. If a 12.5 gram tungsten core AP round could have penetrated 20 mm of armor at 500 meters, a 130 gram AP round would have easily defeated any armor on the battlefield.
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I see where your going, but you can't just increase the amount of weight and then figure it would penetrate alot more! Many things has to be taken into considderation, such as projectile shape, hardness, diameter etc etc...


I used to shoot alot with my Mk4 Enfield, and it is in my experience the most accurate rifle from WW2, and it seems to get more accurate the longer the range believe it or not.


Well sounds like you had alot fun ?

My experience with the 7.92x57mm Mauser round and the 30.06 Springfield round are very similar. Whenever I shoot 7.92x57mm rounds, I only shoot German or Romanian surplus rounds, as i find the American made 8x57mm rounds to be grossly underpowerred

Anyhow we used to shoot alot with the 7.92mm original Mauser rounds, and the 1950's 30.06 Springfield rounds, and found them to be pretty equal !

The normal 7.92mm Ss round will normally penetrate more than the normal 1950's 30.06 round (180gr), at all ranges, but they are both pretty equal actually.

Like you, me and my pal actually once shot up an old Chevy's and Ford's motorblock, with a few German 7.92 S.m.K. rounds and also some Romanian 7.92x57mm surplus AP rounds ,at about 50m distance. The German round would go straight trough block every time, and leave a nice circular shaped intrance-hole, while the Romanian surplus would get stuck inside the motorblock, and leave a strange rectangular intrance hole. (The 30.06 behaved similar to the Romanian 7.92mm AP round if it hit very hard, thick and brittle metal)
 

I really think it's a 10mm plate Soren.


Sure, but like ALL 7.7 mm class ammo, the rate of velocity loss is quite high. Sectional density is the biggest factor in velocity retention, followed distantly by ballistic shape. Scale down a round to 1/2 size, and the sectional density drops in half, even if the ratio the projectile's cross-section to its length is unchanged.

Look at the sectional density of a cube (easy to visualize and calculate) - lets assume a cubic mm weights 0.1 grams for simplicity...

For a 4 mm cube: volume = 4 x 4 x 4 = 6.4 grams. Facing area = 4 x 4 = 16 mm. So the sectional density in grams/square mm = 6.4 grams / 16 mm = 0.4 grams/mm.

Now have the scale...

For a 2 mm cube: volume = 2 x 2 x 2 = 0.8 grams. Facing area = 2 x 2 = 4 mm. Sectional density = 0.8 grams / 4 mm = 0.2 grams/mm.

So the 7.9mm class ammo is going to loose velocity much faster than larger rounds. The only way around this fact is if the round in question is particularly long for its diameter, which is why the .50 BMG (and Brezin UB 12.7mm) do so well at maintaining velocity (combine with their very good ballistic shape).


Sure, but the Hispano 20mm AP rounds were tested at muzzel velocities up to 920 m/s, and had 850 m/s velocity in production variants. The round shape is good for armor penetration. AP and SAP rounds used tungston-carbide penetrators, and solid tungsten shot was tested. So scaling up the side of the round would penetrate a lot more! There is every reason to believe that if a 7.92 mm S.a.M.K. round would penetrate 20mm of armor at 500 meteres, the Hispano 20mm fitted with a similarly proportioned tungston penetrator would penetrate at least 100 mm of armor at 800+ meters.


I like my Enfield too. I have an 1911 model that is in nearly perfect condtion. Next time I dig it out I'll post a photo.


Yes we had a lot of fun. Not much else to do out in the sticks but ride dirtbikes and shoot stuff up

=S=

Lunatic
 
I really think it's a 10mm plate Soren.
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Well I really think its a 12mm plate.(but it could be 10mm, i wouldnt know)
Anyway it doesnt matter, I just know what my experience and books tell me about small arms and their penetrative ability.


I like my Enfield too. I have an 1911 model that is in nearly perfect condtion. Next time I dig it out I'll post a photo.
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Looking forward to it ! You shoot with surplus ?

Yes we had a lot of fun. Not much else to do out in the sticks but ride dirtbikes and shoot stuff up
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The same here ! Except we didnt have dirtbikes, but ATV's
 

Never! I never shot the Enfield that much. I had access to lots of US surplus ammo for free, but not .303 surplus. When I did shoot the Enfield, it was always using brand new ammo. The last time I fired it I used PMC match ammo - about $15 per box of 20.

=S=

Lunatic
 
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