7.92×57mm Mauser vs .303 bullets comparison

[J2_Trupobaw]

A question to people better versed with rifle ammunition than I am.

I remember reading that the German 7.92 bullet and British .303 bullet (as used in WW1, ordinary infantry rifle variants) differed considerably. British used softer, copper/nickel jackets and designed the bullets to deform in body as much as Hague convention allowed. Germans used stronger "gliding" metal for jacket (steel?) to make the bullets pierce body without deforming.

Before introduction of synchronised guns, Roland Garros famously armoured his propeller blades with metal and shot unsynchronised .303 machine gun thorugh it. When his plane was captured by Germans, they discovered copying his design was not practical for them; 7.92 bullets were still able to damage armoured prop that .303 rounds bounced off harmlessly. Or so says the legend.

This may or may not be important for ongoing damage models revision, especially for Flying Circus - if true, German bullets should better at damaging engines and metal elements, and British at wounding pilot and weakening wooden spars. 

I hope someone with ammunition bible on his shelf can give me exact data?

Edited March 23, 2020 by J2_Trupobaw

[Kurfurst]

Steel jackets are a big no-no for any kind of ammunition from rifled barrels. A steel jacket is hard, it would not deform properly in the in the barrel when fit correctly in the grooves.. in the best case, it would wear down the barrel fast, butpossibly bulge or blow it up if it stucks in the grooves and pressure behind it builds up. You probably mix it up with steel cartridge cases which were sometimes used by the Germans to spare brass.

 

Hence why you always use some soft material on the bullet, to protect the barrel and ensure sealing - in the old times they used leather or fabric patches, nowadays we use brass or copper jackets. Even on hard steel cored ammunition. Of course pure lead ammunition can be used as well, but that would lead pretty bad lead deposits on the barrel, which are very hard to clean out, and above a certain velocity, since lead is too soft, could lead to the bullet simply skidding through the rifling without properly spinned, resulting in the bullet tumbling randomly in the air, and would be very inaccurate.

 

Basically the 8x57 is a heavier bullet, with slightly more energy, due to higher bullett mass and more propellant, and thus better stopping power..Also nastier recoil, as its more bullet weight depending. But these difference is small and count more on infantry and even more so, hunting purposes than in air to air use. IMO the practical difference in the latter field between the .303 and the 8x57 is negliable. Both bullets are just too small to be really effective.  

[unreasonable]

I agree that there is little practical difference between the rounds, but from what I can find on the WW1 versions of these bullets (standard ball rounds) the 303 was actually the heavier bullet, although the Mauser had a larger propellant charge giving it a significantly higher muzzle energy. Note that muzzle velocity (and hence energy) depends on what you are firing it out of: there is an optimal barrel length. 

 

303 Mk VII bullet weight 11.28 g

7.92 x 57 Mauser S Patrone bullet weight 9.9 g 

 

For muzzle velocity I find:

 

Vickers 303 - ball 744 m/s

Spandau MG 08 - 900 m/s (I assume with S Patrone: this number looks a little high to me, since elsewhere I find 878 m/s for the Gewehr 98 with a 0.6inch longer barrel )

 

So at K = 1/2 * m * v^2

 

Muzzle energy

 

Vickers+ 303 =  3122 J

MG 08 + S Patrone = 4010 J  

 

The 303 Mk VII was a full metal jacket, hence "legal",  but because it was tail heavy it would tumble on impact, which is bad enough for bodies, but could also then deform or break up. (Like 5.56 NATO).

 

A lighter round will slow faster, so at some point the energy would drop below that of the heavier round, but at normal air combat range the Mauser bullet will usually have slightly higher  energy.  I think KE is captured in the game's DM formulae, but I have not looked at the game files for these rounds. (Perhaps another reason why entente wings feel weaker? Someone who knows how to unpack the files could take a look). 

 

Of course if the game is actually modelling the effect of incendiary/explosive rounds the estimates above might no longer be true. 

 

 

[Kurfurst]

9 hours ago, unreasonable said:

I agree that there is little practical difference between the rounds, but from what I can find on the WW1 versions of these bullets (standard ball rounds) the 303 was actually the heavier bullet, although the Mauser had a larger propellant charge giving it a significantly higher muzzle energy. Note that muzzle velocity (and hence energy) depends on what you are firing it out of: there is an optimal barrel length. 

 

303 Mk VII bullet weight 11.28 g

7.92 x 57 Mauser S Patrone bullet weight 9.9 g 

 

Did some digging.

 

For air combat / long range machinegun (MG 08) fire purposes (better energy retention / range) a heavier bullet was introduced in 1914, the Patrone sS (schweres Spitzengeschoss - heavy 'Spitzer' bullet, torpedo type with no jacket on the base). This weighted 12.8 gram, wasn't used by the infantry much, if at all, expect at the end of the great war, but exclusively for air combat. Later this become standard round in the 1930s for infantry as well. Charge was 2.75 to 2.85 grams (compared to 3.2 grams for the base 8x57 S), quoted speed in a graph - 755 m/sec. Pmax 3300 - 3600 at, depending of powder. So, basically, heavier, slower bullet with less charge, with around 3650 Joules at the muzzle. 

 

No experience with 303s (not many SMLEs around here), but the 8x57 kicks like a mule. Popular for heavy game and tracking wounded game, especially boars in thick vegetation. Plus everyone and their grandmother produced bangsticks in good ole 8x57, and they are still around.

 

I guess this is the one that has RoF in it? I don't have RoF. Just curious about ammunition history.

 

In any case any full caliber rifle round pass through flimsy WW1 aircraft (and for the most part, WW2 ones) without any trouble. Or man. Far less powerful rounds go through several blocks of wood without effort. A poor fellow around here was hit in a hunting accident, by a bullet fired from 3 kilometers (cc. 2 miles) away while fixing his roof - and died. These rounds bcan asically kill at any range - they designed to do, and are an overkill with the idea of 2000+ m volley against massed infantry formation in the turnover of the 19th century. 

Edited April 27, 2021 by VO101Kurfurst

[unreasonable]

QB.Rails posted the unpacked ballistics files in his mod thread: from that we get:

 

Bullet_eng_7-7x56_ap.txt  which includes some readable details such as

 

Bullet speed = "Vickers Mk1"  745 and "Lewis" 745  (which is muzzle velocity in m/s) 

Mass = 0.0115 (which is kg)

 

and Bullet_ger_7-92x57_ap.txt

 

BulletSpeed = "LMG 08/15", 825.0 

Mass = 0.0115

 

So for 303 Vickers we muzzle energy of  3191J, for LMG 08/15 3913

 

I agree that for practical purposes it makes very little difference, especially if you are hitting the aircrew, and both these bullets will go through a brick house and kill someone standing on the other side.  There might be a small measurable effect of how many hits are required to break some structures.

 

Just speculating here but they might have used the same weight for each so that they only have to use one ballistics curve?

 

Edited April 28, 2021 by unreasonable

[357th_KW]

On 4/27/2021 at 2:15 AM, VO101Kurfurst said:

Steel jackets are a big no-no for any kind of ammunition from rifled barrels. A steel jacket is hard, it would not deform properly in the in the barrel when fit correctly in the grooves.. in the best case, it would wear down the barrel fast, butpossibly bulge or blow it up if it stucks in the grooves and pressure behind it builds up. You probably mix it up with steel cartridge cases which were sometimes used by the Germans to spare brass.

Steel alloy jackets for rifle rounds were very common (often with some sort of very thin wash or coating to help reduce wear on the guns bore and reduce corrosion buildup on ammo in storage).  Much of the surplus ammo you find on the market today (some of which was produced in the WWI/II timeframe) is steel jacketed, and even a lot of Eastern European current production is as well.  Steel is just much cheaper than copper.

 

I have an ammo can full of steel jacketed 7.63x39 and another full of 7.62x51 in my garage.  My AK and G3 feed and fire it just fine.  Yeah it produces more barrel wear, but keep in mind that copper was a much rarer and more valuable metal in wartime then steel and a typical gun wasn’t going to survive combat for the period it would take to burn out the barrel anyway.

[cardboard_killer]

28 minutes ago, VBF-12_KW said:

Much of the surplus ammo you find on the market today (some of which was produced in the WWI/II timeframe) is steel jacketed, and even a lot of Eastern European current production is as well.

 

I think you may be confusing the jacket with the casing. I too own a substantial amount of Russian made steel cased ammo; the projectiles (bullets), however, are copper jacketed. I've never seen steel jacketed ammo, although some may exist.

 

 

[Garven]

 

2 minutes ago, cardboard_killer said:

 

I think you may be confusing the jacket with the casing. I too own a substantial amount of Russian made steel cased ammo; the projectiles (bullets), however, are copper jacketed. I've never seen steel jacketed ammo, although some may exist.

 

 

Surplus Greek HXP 30-06 has a copper washed mild steel jacketed bullet. 

Edited May 1, 2021 by 94th_Vernon

[cardboard_killer]

1 hour ago, 94th_Vernon said:

Surplus Greek HXP 30-06 has a copper washed mild steel jacketed bullet. 

 

All the Greek surplus ammo I've seen for the Garand is copper cased, FMJ copper over lead or steel. I've never seen a steel jacketed round. If you have proof that HXP was sold steel jacketed, please post it here. Even a picturre showing the steel jacket would be of interest.

 

Edit: Here is the wikipedia entry for FMJ. It does say that a steel alloy is sometimes used, but as one of the purposes of the jacket is to protect from steel core ammo, it must be a soft alloy.

 

A full metal jacket (FMJ) bullet is a small-arms projectile consisting of a soft core (often lead) encased in an outer shell ("jacket") of harder metal, such as gilding metal, cupronickel, or, less commonly, a steel alloy. A bullet jacket generally allows for higher muzzle velocities than bare lead without depositing significant amounts of metal in the bore. It also prevents damage to bores from steel or armor-piercing core materials. In military nomenclature, it is often labeled ball ammunition.

Edited May 1, 2021 by cardboard_killer

[Garven]

https://www.ammogarand.com/3006-m2-150gr-fmj-ball-30062150100.html 

 

Quote

All rounds are Non-Corrosive, Boxer primed and reloadable. Like most all military ball, the projectile jacket DOES attract a magnet but core is LEAD and NOT steel core.

 

[357th_KW]

https://images.app.goo.gl/Xkzks3dE7ZoCRyMK6
 

Steel jacket with a copper wash.  The projectile attracts a magnet and many ranges ban those ammo types, or at least ask that you don’t shoot them at steel targets.  Wolf actually makes (or made, the whole ammo market is on its head right now) a special copper jacketed variant because it was otherwise impossible to use an AK at many ranges.

 

 

[cardboard_killer]

Okay. But the copper wash provides the barrel protection as if the bullet were copper plated, and the steel jacket is just there to save money/copper not increase penetration.

[Garven]

1 hour ago, cardboard_killer said:

Okay. But the copper wash provides the barrel protection as if the bullet were copper plated, and the steel jacket is just there to save money/copper not increase penetration.

I never suggested that it was for increased penetration.  That was the OP that suggested a mere difference in jacket material could do measurably more damaged to an aircraft engine which I doubt.

Now whether or not the construction (aluminum or wood ahead of a lead core inside the jacket) of .303 MKVII ball has a negative or positive affect on penetration of hard materials is a whole different can of worms, but I don't think it matters in game as both sides likely had AP rounds in their belting.

Edited May 1, 2021 by 94th_Vernon

[unreasonable]

4 hours ago, 94th_Vernon said:

I never suggested that it was for increased penetration.  That was the OP that suggested a mere difference in jacket material could do measurably more damaged to an aircraft engine which I doubt.

Now whether or not the construction (aluminum or wood ahead of a lead core inside the jacket) of .303 MKVII ball has a negative or positive affect on penetration of hard materials is a whole different can of worms, but I don't think it matters in game as both sides likely had AP rounds in their belting.

 

Certainly the RAF/RFC used AP by 1918 - from the aerodrome thread exract from the Australian official history I linked elsewhere:

 

"The methods of loading belts and drums was in the various squadrons officially recorded as follow:-

No. 1 Squadron
3 ordinary, 1 tracer, 1 armour-piercing, 1 Buckingham

No. 2 Squadron
Vickers: 3 ordinary, 1 tracer, 1 armour-piercing.
Lewis: 3 ordinary, 1 tracer, 1 armour-piercing, 1 Buckingham

No. 3 Squadron
3 ordinary, 1 tracer, 1 armour-piercing, 1 Buckingham.

No. 4 Squadron
3 ordinary, 1 tracer, 3 ordinary, 1 armour piercing, 3 ordinary, 1 Buckingham."

 

Probably MkVIIW.z by 1918. They were (70%)  expected to penetrate 10mm plate at 100yards.

 

However in game there is no distinction between ball (ie "ordinary" above) and AP. The bullet file for .303 has some "armour" values in them but I have no idea what they do. 

[Angry_Kitten]

AM i the only one around here who actually shoots?

 

The mild steel jacket actually behaves as AP in the REAL WORLD.   When you are using GENUINE surplus military ammunition. 

 

Take the 30-06 for instanc,e standard military ball FMJ   NON AP variants at 500 yards will go through a world war two helmet from any military when hit dead on.  

       The 5.56x45 requires a dedicated steel core penetrator to do the same, at any range

[unreasonable]

I very much doubt it, but a little research can also help. WW1 era .303 rounds were rather different internally to modern rounds of a similar calibre.

 

From Brit mil ammo site:

 

"Armour Piercing Mark VIIW

The army in France was demanding a better armour piercing bullet in 1917 and so an improved version of the Mark VIIP with a heavier core was developed by Woolwich.

"Cartridge S.A. Ball .303 inch NC Mark VIIW.z"

 

The bullet had an envelope of cupro-nickel clad steel or gilding metal clad steel with a steel core in a lead sheath.

 

For proof, 70% of bullets had to penetrate a 10mm plate at 100 yards range."

 

Compare with standard 303 MkVII ball:  "The bullet was flat based with an 8CRH ogive and a composite core, the forward part usually being aluminium and the rear part a 98/2% lead/antimony alloy. During wartime the aluminium tip was replaced by compressed paper, fibre or ceramic." You can find nice pictures online: that "tip" extended almost all the way down to the shoulder. 

 

That the RAF used AP in a mix with "ordinary" (ie ball) is a documented fact, done for the simple reason that .303 ball did not have very good AP characteristics.

 

 

[Avimimus]

That is quite interesting.

 

One has to remove something like 2mm to 4mm of penetration due to yaw induced when the bullet passes through the skin of the aircraft (i.e. the bullet will have started to tumble slightly prior to reaching the armoured plate).

 

However, that is still good enough that at some point under 100m the bullets should be able to penetrate the armour of essentially all German bombers (armour climbed from ~6.5mm to 8mm over time)... so the Hurricane should be shredding internal components and crew - at least in cases where the rounds are good AP (i.e. in the 70%), fired at close range, and not tumbling too much... because that doesn't describe all of the rounds, the effective rate of fire of penetrating rounds will be lower - but it should still be quite effective. I wonder if we've been under-estimating the effectiveness of these small-calibre rounds?

 

Also, does anyone want to expand the analysis to the ShKAS?

 

 

[unreasonable]

Some combination of .303 AP and incendiaries managed to shoot down a large proportion of the almost 2,000 aircraft lost by the Axis in the BoB. The losses were not often due to AA, other air-air weapons also played a minimal part. Even allowing a large percentage as pure accidents, one cannot say the .303s were ineffective, against the armour and other protection of the planes of 1940.  

 

As far as I can see, the late WW1 AP bullet was the same design as used into WW2, but I am not sure exactly when the MkVIIW came into service. The ones in use for WW1 might have been more often the MkVIIF which was inferior. 

 

But with a light round you would have to get very close to get AP effect, and that has implications for effective firing time, especially if you are closing on bombers.  That should translate into the game fairly directly, if the devs have their AP calculations roughly right.

Edited May 13, 2021 by unreasonable