Well I'll be an SOB (shatter gap) -1 reply

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axkgkadragon

GF is my bext friend *hugs GF*

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16th November 2003

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#1 13 years ago

while scouring an info site i came across some things:

Piercing Caps At an early stage in World War II the phenomenon of “shatter” was encountered. The term is applied when a projectile failure occurs at high impact velocities, with its complete collapse. At lower velocities against the same target plate normal penetration may occur without any projectile break-up. As the velocity increases the projectile shatters and fails to penetrate. As velocity increases still further the shattered pieces can once again penetrate the target plate. The band of velocities between the onset of shatter failure and the point at which penetration again occurs (this time by the shattered pieces) is called the “shatter gap”. In the case of the British 2–pounder gun this gap occurs at normal combat ranges.

Shatter is mostly eliminated by adding hard steel piercing caps to the nose of the projectile. This directs the impact shock away from the tip of the shell to the shoulders, preventing the tip from shattering at high impact velocities, and the projectile is called an APC (armour piercing capped) projectile. APC allows FH armour, and thicker slabs of overmatching homogeneous armour, to be defeated without the shattering of the projectile. Often a ballistic cap is fitted over the piercing cap to improve flight characteristics and the round is then referred to as an APCBC (armour piercing capped with ballistic cap) projectile.

USA ammunition nomenclature in World War II did not recognise the addition of a ballistic cap, so it rather confusingly uses “APC” for an APCBC projectile.

“Use of a piercing cap does not guarantee that the projectile will not shatter.”

but the most interesting piece:

Use of a piercing cap does not guarantee that the projectile will not shatter. In the case of the USA 76mm M1 gun firing an M62 APCBC projectile the shatter gap occurs between about 200m and 1200m, when the target plate is around 100mm thick and hard, such as typical German vehicle armour. That is why the USA 76mm M1 gun was a Tiger I killer on the charts, but not in real life. When it was fired in tests it tended not to shatter because USA test plate was somewhat soft, so the shatter gap was not revealed by the USA testing and development program.

wow.....i had always had a hunch that the 76 was a little over powered

anyway heres the link to the site: http://wwiiol.vwgn.com/index.php?title=Ammunition#Armour_Piercing




emonkies

I'm too cool to Post

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17th July 2003

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#2 13 years ago

Yup, you talk about rushing through the drawing board, it wasnt til late in 1944 that the redesigned M1A1C and the M1A2 made its appearance with redesigned APCBC projectiles such as the M79, and M93 HVAP.

Supposedly the improved late war US AP rounds that were so effective were reverse engineered from PzGr39 and PzGr40 rounds.

M1A1c and M1A2 could usually be identified by the muzzlebrakes but some crews took them off as the back blast tended to kick up alot of dust revealing the firing position. This also caused extra wear on the recoil mechanism and the vehicle itself.

At one point after El Alamein and before Italy the Brits captured huge stocks of PzGr39 ammo for the PzIV F2's 75mm long barreled gun.

Seeing a opportunity some resourceful Brits took some measurements and discovered that if the PzGr39 round was disassembled and the AP projectile removed from its casing an turned down a wee bit on a lathe they could mount the PzGr.39 APCBC projectile on top of a US 75mm shell casing. A small production line was set up in the rear area and thousands upon thousands of rounds were assembled. BUT The Brits removed the explosive filler it seems so no exploding inside the tank effects.

But penetration when hit went up considerably and supposedly prompted the Brits to redesign their AP shells for better penetration.




axkgkadragon

GF is my bext friend *hugs GF*

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#3 13 years ago

now dont tell me that only the two ww2 freaks on the GF care about this.....




Arisaka

Staff suffers from PCD

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16th August 2004

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#4 13 years ago

of course not, but what can we add? the facts have been put down, the rest is coding - i can't contribute there either. it's obvious that this is an important feature, that ought to be included.




axkgkadragon

GF is my bext friend *hugs GF*

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16th November 2003

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#5 13 years ago

well....maybe dev thoughts then?




roterschnee

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8th January 2005

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#6 13 years ago

This is bloody interesting IMHO :) I've always meant to learn a bit more about the way ammunition works. Are there any sites or books (apart from the one at the top of the thread) that people have found useful?




emonkies

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#7 13 years ago
bbble

Don't mess with my Teddy!

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#8 13 years ago
In the case of the British 2–pounder gun this gap occurs at normal combat ranges.

It is a lousy AT gun (the 8th army did not have a decent gun until the 6pdr arrived) yet ingame it is über :( There are some points in the ammunition technology which is overlooked ingame. One thing I have always wanted to see is dramatically more efficient allied artillery in the battle of the bulge and onwards, thanks to the proximity fuse.




emonkies

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#9 13 years ago

The 2lbr worked well enough but lacked killing power at range which meant the A/T gun crews had to be exposed to enemy fire til the range closed to killing range.

When the Germans started uparmoring their vehicles, the 2lbr was no longer effective and was replaced by the 6lbr but unfortunately the 6lbr still wasnt available in the numbers needed even after the 2lbr was considered inadequate. IIRC 6lbrs were still in short supply at El Alamein.




roterschnee

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#10 13 years ago
Anlushac11This may take you a day or two to get through but it will give you lots of info http://www.quarry.nildram.co.uk/ballistics.htm And http://www.quarry.nildram.co.uk/highvel.htm And http://www.freeweb.hu/gva/weapons/introduction.html#Weapon_Identification

Cheers :)