KillaKiwi

76.2mm BR-350B "Special" - Any known sources?

Does anyone know another source for this special BR-350B round that is mentioned in WW2 Ballistics and used in the game?

According to WW2 Ballistics it was some rare shell that appeared in 1943 in low quantities, if I remember correct.

It was supposedly specially heat treated, which honestly doesn't make any sense for a blunt nosed shell.

Heat treatment is applied to regular sharp nosed AP shells to harden the nose to prevent it from breaking/shattering too easily.

 

The reason the Soviets used blunt shells in the first place is because they weren't able to mass produce sharp nosed AP in sufficent quality so they just went for cheap and easy to produce blunt shells.

 

According to a German document on the zis-3 gun there was a special round available which had around 1.5kg propellant compared to the regular 1kg.

This would allow the shell to reach a respectable 740m/s compared to the normal 660m/s.

 

Maybe they just mistoke the round with more propellant some special shell or this "heat treated" round was infact a sharp nosed AP shell.

If its the first case I doubt the T-34 tanks were able to fire those rounds since they didn't have muzzle breaks and this might potential damage the gun, turret or the crew.

 

 

 

Edited by KillaKiwi
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Different versions of BR-350B

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image.thumb.png.dc4a117a12369dd802d50d53image.png.503fa18d1ac4fc0b6ea2277f8c8f8dimage.png.7f675d96d5b82ae613f5c5c9f36d5e

 

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Yeah you posted that in the topic I linked. Both shells are basically the same but the one on the right is nearly completely flat. If that BR-350B round ever had better penetration then because it was tested against Soviet high hardness armor which is easiliy defeated by APC and flat nosed AP shells compared to sharp nosed AP shells. Against regular medium hardness armor it would result in even worse penetration.

 

Honestly this special round seems like a myth that was spread in one article from 2003 that no longer exists on the web.

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@Conraire do you know whats the difference between the BR-350 and BR-354 shells? Both are 76.2mm.

To me it seems like that the field cannons used the BR-354 while the tank guns used the BR-350 even though they seem identical.

-> http://michaelhiske.de/Wehrmacht/Heer/HEER/HDv_119/116/Anhänge/Bilder/Bild_11.htm

and here is the round with increased propellant, supposedly named BR-354C

http://michaelhiske.de/Wehrmacht/Heer/HEER/HDv_119/116/Anhänge/Bilder/Bild_12.htm

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31 minutes ago, KillaKiwi said:

@Conraire do you know whats the difference between the BR-350 and BR-354 shells? Both are 76.2mm.

To me it seems like that the field cannons used the BR-354 while the tank guns used the BR-350 even though they seem identical.

-> http://michaelhiske.de/Wehrmacht/Heer/HEER/HDv_119/116/Anhänge/Bilder/Bild_11.htm

and here is the round with increased propellant, supposedly named BR-354C

http://michaelhiske.de/Wehrmacht/Heer/HEER/HDv_119/116/Anhänge/Bilder/Bild_12.htm

BR-354 is mostly cartridge name, UBR-354 to be exact, then you have with in case of BR-350B is UBR-354B

 

http://michaelhiske.de/Wehrmacht/Heer/HEER/HDv_119/116/Anhänge/Bilder/Bild_11.htm

it is UBR-354A round with shell BR-350A (designation is at bottom of projectile)

 

http://michaelhiske.de/Wehrmacht/Heer/HEER/HDv_119/116/Anhänge/Bilder/Bild_12.htm

2 is UBR-354C with larger propellant but shell is still BR-350A

 

only exceptions i know are BR-354P and Sh-354T  along with older pre 1930s rounds F-354, F-354F and Sh-354

still there is 76mm APHEI-T, BZR-350B

 

Edited by arczer25
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24 minutes ago, arczer25 said:

BR-354 is mostly cartridge name, UBR-354 to be exact, then you have with in case of BR-350B is UBR-354B

 

http://michaelhiske.de/Wehrmacht/Heer/HEER/HDv_119/116/Anhänge/Bilder/Bild_11.htm

it is UBR-354A round with shell BR-350A (designation is at bottom of projectile)

 

http://michaelhiske.de/Wehrmacht/Heer/HEER/HDv_119/116/Anhänge/Bilder/Bild_12.htm

2 is UBR-354C with larger propellant but shell is still BR-350A

 

only exceptions i know are BR-354P and Sh-354T  along with older pre 1930s rounds F-354, F-354F and Sh-354

still there is 76mm APHEI-T, BZR-350B

 

Ah right. I didn't notice that the casing was called 354 but the shell 350.

When was the BR-350B introduced? Because in the German doc from 1942 it only shows the BR-350A but in another doc theres also a BR-350 which looks a lot like the BR-350B.

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15 minutes ago, NO_DRAGON said:

01.thumb.JPG.5d8029db23d642046f5850b5e1f

Only problem that according to that what is says it is this but it still have br-350b designation



image.png

Also we have small cavity Br-350b in game.

 

Unless it's talking about BZR-350B

 

1 hour ago, KillaKiwi said:

Ah right. I didn't notice that the casing was called 354 but the shell 350.

When was the BR-350B introduced? Because in the German doc from 1942 it only shows the BR-350A but in another doc theres also a BR-350 which looks a lot like the BR-350B.

I don't know to much things happened at that time to have exact date, along with changes to shell itself

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43 minutes ago, arczer25 said:

Also we have small cavity Br-350b in game.

Doesn't look like a smaller cavity. Just less weight due to the mix of explosive and incendiary content maybe :dntknw:

Or maybe its the other way around and the tnt+incendiary weighs more.

Edited by KillaKiwi
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3 hours ago, KillaKiwi said:

Doesn't look like a smaller cavity. Just less weight due to the mix of explosive and incendiary content maybe :dntknw:

Or maybe its the other way around and the tnt+incendiary weighs more.

I misspelled, should be different shapes cavity.

Due to it walls are thicker at 25mm compared to 19mm

 

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17 hours ago, arczer25 said:

 

  Hide contents

 

 


image.png
 

 

Also we have small cavity Br-350b in game.

 

Unless it's talking about BZR-350B

 

I don't know to much things happened at that time to have exact date, along with changes to shell itself

I'm thinking this is a later modification. The Russian manual on 76mm ammunition from 1949 doesn't list MD-6 as one of the fuze options for BR-350B.

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24 minutes ago, ADrunkMoth said:

I'm thinking this is a later modification. The Russian manual on 76mm ammunition from 1949 doesn't list MD-6 as one of the fuze options for BR-350B.

possibly its just become obsolete.

also noticed it isn't BR-350B, but BZR-350B

image.png

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1 hour ago, arczer25 said:

possibly its just become obsolete.

also noticed it isn't BR-350B, but BZR-350B

image.png

So thats the later one? It has 0.12kg filler while the other had just 0.6 even though the cavity looks as big.

From my previous explanation: If this is the latest shell it would make sense since the other shell, being almost completely flat, would have worse penetration compared to this version which isn't as flat.

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12 minutes ago, KillaKiwi said:

So thats the later one? It has 0.12kg filler while the other had just 0.6 even though the cavity looks as big.

From my previous explanation: If this is the latest shell it would make sense since the other shell, being almost completely flat, would have worse penetration compared to this version which isn't as flat.

not latest ones, it just have different designation: BZR-350B vs BR-350B

on round you have the same year as 1 BR-350B 1942.

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Accoding to this website the Projectile

BZR is 3 mm longer than the BR one.

 

http://bulletpicker.com/projectile_-76mm-aphe-t_-br-35.html

 

and some other finds

 

http://www.weapon.df.ru/ammo/76mm/divis1-e.html

 

http://english.battlefield.ru/tank-armament/79-specification-and-armor-penetration.html

Edited by NO_DRAGON
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I just noticed that its literally written in the German manual:

image.png.d741236695248175c1782dce1e7f6c

Translation:

The Armorpiercing shells are painted grey. They have a a blue circle under the ?Zentrierwulst?.

In wartimes the PzGr. shells get oiled instead of painted. The blue circle is kept.

The bottomfuze contains a tracer. The ballistic cap of the PzGr. is made from light alloys

It's forbiden to use PzGr. without (ballistic) caps; and should be returned to ammo supply.

The 7.62cm PzGr.Patr. 300/3 Tracer (r) - russian УБР 354 С - has a label on its cartridge:

"СТЕЦЙАЛБНЫЙ" = "Special"

and

 "СТРЕЛ ТБЯТОЛОБКО ПО ТАНКАМ" = "Only use against tanks".

The 7.62cm PzGr. 300 tracer (r) - УБР 354 A - doesn not have this label.

 

Then they show the penetration of the "special" shell according to Soviet sources which I mistook in my other topic for the values of the BR-350A shell.

 

So I guess that clears things up. As I've suspected is this "special" shell nothing more than your regular BR-350A or B fired with increased propellant from field and anti-tank guns.

I highly doubt these special shells would be used by tanks as the recoil would increase substantially without a muzzle break.

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14 hours ago, KillaKiwi said:

I just noticed that its literally written in the German manual:

 

Translation:

The Armorpiercing shells are painted grey. They have a a blue circle under the ?Zentrierwulst?.

In wartimes the PzGr. shells get oiled instead of painted. The blue circle is kept.

The bottomfuze contains a tracer. The ballistic cap of the PzGr. is made from light alloys

It's forbiden to use PzGr. without (ballistic) caps; and should be returned to ammo supply.

The 7.62cm PzGr.Patr. 300/3 Tracer (r) - russian УБР 354 С - has a label on its cartridge:

"СТЕЦЙАЛБНЫЙ" = "Special"

and

 "СТРЕЛ ТБЯТОЛОБКО ПО ТАНКАМ" = "Only use against tanks".

The 7.62cm PzGr. 300 tracer (r) - УБР 354 A - doesn not have this label.

 

Then they show the penetration of the "special" shell according to Soviet sources which I mistook in my other topic for the values of the BR-350A shell.

 

So I guess that clears things up. As I've suspected is this "special" shell nothing more than your regular BR-350A or B fired with increased propellant from field and anti-tank guns.

I highly doubt these special shells would be used by tanks as the recoil would increase substantially without a muzzle break.

by sources there are given 3 muzzle velocities: 655m/s, 662m/s and 680m/s, maybe special rounds are for 680m/s.

only that sources don't match each other in that term..

interesting fact is that you have 76mm ZiS 3 gun with is L51.6 caliber compared to 76mm ZiS 5/F-34 L41.5 using the same cartridge 76.2 × 385 mm have generally listed MV as 680m/s

while for 76mm ZiS 5/F-34 L41.5 you have that varying 655-680m/s

680m/s is in Russian document for T-34 and KV-1 so they could possibly fire it. Domestic Armoured Vehicles



7G3k7gJ.png?1

CKQWWaU.png

it could be like ADrunkMoth sad: BR-350B 655m/s, BR-350A 662m/s and then using special cartage 680m/s

 

 

 

 

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US hardness testing of the BR-350B from captured projectiles from the Korean War: http://www.dtic.mil/dtic/tr/fulltext/u2/014698.pdf

 

From the report: 

 

CONCLUSIONS

 

1. The subject 76MM APHE shot is similar in general design to Soviet shot of other calibers which have been previously examined, reference Watertown Arsenal Laboratory Report No. WAL 762/ 582(c) "Metallurgical Examination of Soviet 45MM, 57MM, and 85MM APHE Projectiles, FMAM 11 2'1, 1935, and 2175. "

 

2. The steel employed for the 76MM shot body differs radically in composition from shot steels employed in this country. The low carbon content (0. 3470) results in a relatively low hardness (Rockwell C 45 in the nose ). American shot generally contain from 0.50 to 0.6070 carbon and are hardened to approximately Rockwell C 60 in the nose. In addition, the high silicon content ( l. 5470,) which is typical of Soviet projectile and armor steels, indicates the use of this element as a deliberate alloying agent whereas it is usually present in only residual quantities in domestic alloy steels employed for projectiles.

 

3. The silicon-chromium steel has insufficient hardenability to completely quench hardento martensite in a 76MM shot as indicated by the large amount of rejected ferrite observed in the nose of the shot. In addition, the heat treatment employed in hardening the shot resulted in the base having a very considerable amount of ferrite and pearlite, and probably involved quenching only the forward part of the shot with the base being air cooled from an elevated temperature. As a consequence of the above, the shot would probably tend to fracture in a brittle manner upon impact against moderately severe targets.

 

4. The notable features of the subject shot, flat nose and circumferential notches above the bourrelet, indicate that the shot was probably designed to be effective in defeating moderately thin (up to 2" thick) armor under conditions of attack involving moderate to high obliquities of impact.

 

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34 minutes ago, arczer25 said:

interesting fact is that you have 76mm ZiS 3 gun with is L51.6 caliber compared to 76mm ZiS 5/F-34 L41.5 using the same cartridge 76.2 × 385 mm have generally listed MV as 680m/s

The ZIS-3 has the around the same barrel lenght as the F-34 or ZIS-5.

The German doc shows 680m/s for the HE shells (6.22kg) while the APBC (6.3k) shows 662m/s. All shells are fired with the same propellant charge.

Soviet gun generally seem to feature similiar velocity for their AP and HE rounds.

So I suspect that the 680m/s velocity is only for the HE shell and it was also quoted for the AP rounds by mistake.

 

A tank "special" shell that increases the velocity from 655m/s to 680m/s would hardly make a difference for APBC penetration.

I guess theres the possibility that they increased the charge for the BR-354B to match the velocity of the HE shell but then there would be nothing special about this shell.

 

As it stands the this "special" BR-350B was nothing more than a regular BR-350B fired at higher velocity. Thats the only explaination that would explain the increase in penetration for a flat nosed shell.

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6 minutes ago, RedWitch4 said:

US hardness testing of the BR-350B from captured projectiles from the Korean War: http://www.dtic.mil/dtic/tr/fulltext/u2/014698.pdf

 

Quote

Blunt nosed projectiles are especially effective against undermaching armor at all obliquities of attack, particulalry when fired from guns designed for low muzzle velocities.

 

Which makes sense, at low velocity a shell can only penetrate undermatching armor and having a blunt shell helps with that since against undermatching armor the armor is defeated by pluging and not pushing the armor out of the way.

Again showing how high velocity guns like the 85mm, 100mm and 122mm should have very poor penetration using flat nosed shells.

 

Quote

Against overmatching armor and low obliquities, blund nosed shot become inefficent and are muss less effective than sharp nosed shot.

 

Also interesting -> http://www.dtic.mil/dtic/tr/fulltext/u2/a443218.pdf

Quote

....

It has been determined that highly sloped armor targets be more effectively defeated by shot whose noses undergo fracture, permitting the blunt body section which remains to punch through the armor.

Under this condition of attack, (highly sloped armor) shots whose noses remain intact tend to recochet off the armor. Thus the notching of ogival shot promotes their fracture to form blunt nosed projectiles when attacking sloped armor targets.

 

Which is the same theory I used to explain the effectiveness of AP shot against high obliquity armor.

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Guys why you coundt ask Yuri Pasholok , Peter Samsonov or even Andrey Ulanov ?These people know english sufficiently and have access to first-hand sources .

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On 11/08/2018 at 11:38, arczer25 said:

by sources there are given 3 muzzle velocities: 655m/s, 662m/s and 680m/s, maybe special rounds are for 680m/s.

As I've said, the 680m/s is probably for the HE shell and I just found the evidence for that:

uLjZugM.png

 

It shows the PT-76s gun from 1955 with 655m/s for the AP shell and 680m/s for the HE shell. That gun is essentially the same as the F-34 performance wise.

Geez the amount of errors we have in-game about the performance of Soviet ammunition is just ridiculous.

 

This whole idea that some sort of special BR-350B shell exists just came from one random dude on the internet without any backup to support it.

Of course the authors from WW2 Ballistic took that and also turned Soviet AP rounds into what we have now in-game, the holy grail of AP shells :facepalm:

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From the "Encyclopedia of Russian Artillery", information on 76mm projectiles fired from 40 caliber cannons (ZiS-3 and F-34 fall under this). OF-350 (HE) @ 680m/s, BR-350A @ 662m/s and BR-350B @ 655m/s. Published in 2000, no mention of any "special" high velocity rounds.

Spoiler

474413237_76mm40calibertableencyclopedia

Spoiler

1693549229_76mm40caltableencyclopediaofa

 

Fired from their larger 50 caliber cannons AP only reached 690m/s. 680m/s from the 40's doesn't add up.

Spoiler

1077825570_76mm50calAPtableencyclopediao

 

 

 

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In-game the velocity for the BR-350B is 655m/s which is correct. But the weight is the same 6.3kg as the BR-350A and of course it has the wrong penetration from WW2 Ballistics.

I made a bug report about the wrong performance of Soviet APBC shells yesterday.

My calculation matches with Soviet penetration data for IP which shows that my calculation is correct.

 

The performance isn't that diffferent. 94mm at 0m but 70mm at 2000m. These flat shalls lose little penetration over range since they penetrate with momentum and not kinetic energy.

Slope performance wise these shells would penetrate as much as regular AP shells which are severly underperforming in the game.

That would mean that the BR-350B would not be able to penetrate the front of either Sherman tank :dntknw:

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It might be that the B version was hardened to the western standards of 51-60 Rockwell hardness.

 

The book goes to detail in places as to how especially the 45 mm was extremely xxxx early on due to poor metalwork.

 

 

If I remember it correctly, PzGr. 39 for the 88 mm gained the boost in penetration due to a reduced cavity, and higher hardness + some other metalworking features over the standard 88 mm PzGr. used for flak.

Edited by Ulatersk
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