Russian WWII 85mm Antiaircraft Gun Ammunition

[Eggburt1969]

Here are my 85mm rounds. There are two issues:
1. The BK-2M has a KTM-1 fuse. This is not correct. The fuse should be a GPV-2. Might anyone have two such spare fuses?
2. The O-365K with the T-5 fuse and brass protector is not labeled correctly. I believe it to be a O-365 two piece projectile. The HE round on the right is a O-365K one piece round with KTM-1 fuse.

According to the ammo section of the 1948 manual on the ‘85 mm Model 1939 Anti-Aircraft Gun’ I have, there's a few problems here.

The first is that the 53-O-365K isn't listed as using the T-5, nor the TM-30 or VM-30 time fuzes (they aren't 'fuses'). The T-5 and the other time fuzes were for use with the 53-O-365 projectile.

The second is that the 53-O-365 is only listed as being one-piece. It's the 53-O-365K that is listed as having one-piece and two-piece versions. The two-piece version had an internally threaded nose well (M52×3.0) into which a threaded fuze adapter/booster assembly was screwed. The KTM-series fuze was then screwed into this adapter. The one-piece version of the 53-O-365K had a slightly longer nose and a fuze well that was threaded for the KTM-series (M36×2.5).

I should be noted though that the fuze well of the 53-O-365 and the nose well of the 53-O-365K two-piece supposedly share the same M52×3.0 thread. As such a T-5, TM-30 or VM-30 time fuze could be screwed into a the 53-O-365K two-piece if its fuze adapter/booster assembly is first removed.

The info in question from the manual is below.





Also, in the 1962 manual I have for the 3BK2/3BK2M (3БК2/3БК2М) HEAT-FS-T projectiles, well 3UBK1/3UBK1M (3УБК1/3УБК1М) rounds, they are listed with the GPV-1 (ГПВ-1) point-initiating based-detonating (PIBD) fuze; more specifically it’s a piezo-electric initiated spit-back design. The rounds are still listed with the GPV-1 fuze in the 1982 manual I have of the D-44 divisional gun?

For note, in the manual I have that dates to 1968, the GPV-2 fuze is listed for the 3BK7/3BK7M (3БК7/3БК7М) HEAT-FS-T projectiles of the 3UBK5/3UBK5M (3УБК5/3УБК5М) rounds. The 3UBK5/3UBK5M rounds (and hence projectiles) were for the 85 mm D-48 and D-70 guns.

 

[M8owner]

May I request that you post images here of the BK-2M round from the D-44 manual here? I do not have the manual.

 

[M8owner]

Comparison of O-365 vs. O-365K high explosive rounds.

 

[Eggburt1969]

May I request that you post images here of the BK-2M round from the D-44 manual here? I do not have the manual.

The 3BK2M is just a 3BK2 with a copper and not steel shaped charge liner. That’s about the only difference I’m aware of? This is the same for most, if not all, the ‘3BK’ series of HEAT-FS projectiles.



Diagrams of the 85 mm 3BK2 (ЗБК2) and/or 3B2KM (ЗБК2М) HEAT-FS-T projectile for the D-44. From a 1962 manual (1962) and a 1983 manual (right).



For comparison, a diagram of a 85 mm 3BK7 (ЗБК7) and/or 3B7KM (ЗБК7М) HEAT-FS-T projectile for the D-48 or D-70 guns from a 1968 manual.

Data on the use of the just the GPV-1 fuze with the 3BK2/3BK2M.



The above from the 1962 manual on the 3UBK1/3UBK1M round.



The above from the 1983 manual on the D-44 gun.

So from 1962-1983, official Russian data states that a 3BK2 (3BK2M) projectile was, as standard, fitted with the GPV-1 (ГПВ-1) fuze. This contradicts both the DIA projectile guides and the 2004 EOD guides. Hmm, I wonder which source is more likely correct?

Comparison of O-365 vs. O365K high explosive rounds.

I think this, the page capture from the US DIA document, is the problem, not your projectiles.

From working on Russian weapons from the Cold War-era for many years, I have found there to be a lot of data from Western sources of the era that do not marry up with what’s in official Russian sources (manuals, etc.). As such, what do you believe, Western intelligence sources, or the horse's mouth as to say, Russian sources? We've already seen just a few of the errors in the 2004 EOD guides for example!

As far as I can tell from Russian sources that I have, you had these 85 mm HE projectiles:

1. The single-piece steel 53-O-365 anti-aircraft fragmentation projectile, which had a short nose with a wide fuze well for the T-5, and later the TM-30 and VM-30 fuzes.
2. The two-piece steel 53-O-365K ground target projectile, this is stated to be the 53-O-365 but fitted with a threaded fuze adapter/booster assembly of the KTM-series.
3. The single-piece steel 53-O-365K ground target projectile, that had a full nose with a small fuze well for the KTM-series fuzes.
4. The single-piece 53-O-367A steel and cast iron mix (steely cast iron) ground target projectile, that had a full nose with a small fuze well for the KTM-series fuzes.

The second one in the list (the two-piece 53-O-365K) is likely why you see projectiles as stencilled with O-365 but with adapter in place. If supplied in that state from the factory they should have been stencilled as O-365K and not O-365.
For note, the 53-YO-367 (53-УО-367) round, which is stencilled up as YO-367, uses a 53-O-365K projectile with a reduced charge. There’s no 53-O-367 projectile as far as I can tell.

There are also these projectiles listed online, but they aren’t in any manuals I have.

• 53-O-365Zh (53-О-365Ж) sintered iron driving band; you’d have thought this would be 53-O-365KZh as it says it’s for KTM-series fuzes?
• 53-O-365KV (53-О-365КВ) fuze well for V-429 fuze.
• 53-O-365ZhV (53-О-365ЖВ) sintered iron driving band and fuze well for V-429 fuze.
• 53-O-365A (53-О-365А) steely cast iron projectile.
• 53-O-365AZh (53-О-365АЖ) steely cast iron projectile with a sintered iron driving band.
• 53-O-365AZh (53-О-367АЖ) steely cast iron projectile with a sintered iron driving band.
• 53-O-365AV (53-О-367АВ) steely cast iron projectile with a fuze well for V-429 fuze.
• 53-O-365AZhV (53-О-367АЖВ) steely cast iron projectile with a sintered iron driving band and fuze well for V-429 fuze.
• 3O2 (3O2) (Three ‘Oh’ Two) high-strength cast iron projectile.

 

[Nabob]

And then You find this

BTW KTM-1 thread is Withworth 36,14 x 1/10

Bob

 

[Eggburt1969]

And then You find this

BTW KTM-1 thread is Withworth 36,14 x 1/10

Bob

Hmm, all the US data I've got says M36×2.5 (nominally 36 × 2.5 mm), which is pretty close to to your figure. If its 36.14 mm that's close to Withworth 1½ fine thread (British Standard Fine - BSF), but that's 8 TPI (3.175 mm)? Frankly I'm not all that hot of older thread sizes?

As to the pictures, what are they? A 53-O-365 fitted with a VM-30 mechanical time fuze with its protective cover in place? If yes, I did mentioned that the 53-O-365 could be fitted with the T-5 (detonative output) powder train time (PTT) fuze, or the TM-30 or VM-30 mechanical fuzes already?

 

[Nabob]

Please look closely at the designation, it is O-365-K.

The russian thread sizes are somewhat odd. It is not standard metric, but used for more than 100 years makes it a standard of itself.
In Czech EOD the thread is one of the ID features. We had to switch from standard metric to this soviet thread size in the 1950s. So you can find models with both threads.

 

[MINENAZ16]

Please look closely at the designation, it is O-365-K.

The russian thread sizes are somewhat odd. It is not standard metric, but used for more than 100 years makes it a standard of itself.
In Czech EOD the thread is one of the ID features. We had to switch from standard metric to this soviet thread size in the 1950s. So you can find models with both threads.

Damned I thought I was starting to understand different designs and designations (I'm lost with your O-365-K with O-365 shape)

 

[M8owner]

This is a factory BK-2M cutaway. It is interesting that the fuse has to generate enough force to pierce an aluminum cap in order to set of the shaped charge. I have never seen anything but a clear path to the detonator before in such designs.

 

[Nabob]

Damned I thought I was starting to understand different designs and designations (I'm lost with your O-365-K with O-365 shape)

No, I am sure Eggburt was right, as he always is (almost ).
Somebody probably messed with the projectile. I do not quite remember where I got the picture from. It seems to be a nice collection there. This just underlines the problem with gathering reliable data. If possible I try to rely on original data of the period. I wish I could have factory drawings with all the change sheets.
Here some pictures from a 1957 document.

Bob

 

[Eggburt1969]

This is a factory BK-2M cutaway. It is interesting that the fuse has to generate enough force to pierce an aluminum cap in order to set of the shaped charge. I have never seen anything but a clear path to the detonator before in such designs.

Yes, very weird as spit-back charge guide/liner protector - the truncated cone shaped structure you are referring to - normally has a hole in its apex area?

This is to allow the very directional spit back charge's output (a projectile or jet) to past though unimpeded, but to block any additional wider-angle fragments from striking the outer surface of the liner.

The configuration shown on the 3BK2M image (and it seems in the diagrams), would result in the projectile or jet striking the flattened area (meplat) of this truncated cone. This would result in a spall cone being formed as the projectile or jet penetrates and then passes through it. This spall would then spatter and damage outer surface of the liner. This is not something you want, as it's this surface that forms the shaped charge's jet and its very sensitive to damage!

As such, that configuration of spit-back charge guide/liner protector sort of defeats the object of it being their in the first place?

 

[Eggburt1969]

Please look closely at the designation, it is O-365-K.

The russian thread sizes are somewhat odd. It is not standard metric, but used for more than 100 years makes it a standard of itself.
In Czech EOD the thread is one of the ID features. We had to switch from standard metric to this soviet thread size in the 1950s. So you can find models with both threads.

Just see the above post. I've chopped it out, removed the extraneous stuff, and tweaked it for clarity.

1. The two-piece steel 53-O-365K ground target projectile, this is stated to be the 53-O-365 but fitted with a threaded fuze adapter/booster assembly for the KTM-series of fuzes.
   

The two-piece 53-O-365K is likely why you see projectiles as stencilled with O-365 but with adapter in place. If supplied in that state from the factory they should have been stencilled as O-365K and not O-365.

 

[M8owner]

I can look down the fuse well of my complete BK-2M projectile, and the spit-back charge guide/liner protector cap is in place. It has no hole in it.

 

[Eggburt1969]

I can look down the fuse well of my complete BK-2M projectile, and the spit-back charge guide/liner protector cap is in place. It has no hole in it.

I don't doubt that it doesn't have a hole. I'm just saying that it's weird and sort of defeats the object of it being there in the first place for the reasons I mentioned?

In addition, penetration of this cap would slow it down the output of the spit-back charge. Thus the time taken for the output to travel from the spit-back charge to the detonator assembly, which is in the area at the base of the extension tube that extends from the liner's apex, would be longer. Again not something you want. What you want is for the time from impact to the initiation of the main charge to be as short as possible. The longer this time is, the closer the liner gets to the face of the target, and hence the shorter the stand-off. A shorter stand-off generally means less penetration.

All very weird.

 

[Nabob]

Just see the above post. I've chopped it out, removed the extraneous stuff, and tweaked it for clarity.

1. The two-piece steel 53-O-365K ground target projectile, this is stated to be the 53-O-365 but fitted with a threaded fuze adapter/booster assembly for the KTM-series of fuzes.
   

The two-piece 53-O-365K is likely why you see projectiles as stencilled with O-365 but with adapter in place. If supplied in that state from the factory they should have been stencilled as O-365K and not O-365.

This would be an exact opposite.
Someone removed the adapter for the KTM and fitted a MT fuze.
I was an ammunition officer for only a short time, but I cannot imagine the operation being done outside factory or ammunition base. Storage depots have strict rulles for handling ammo and changing fuzes is something not normaly done on "eastern" ammunition by the troops.
If this would be done at an ammunition base, it would follow exact and detailed procedure protocol and propper markings would me applied.

Bob

 

[M8owner]

Here are some pictures of the T-5 fuse compared to a T-7.

 

[Nabob]

You have a T-7umg, a converted T-7 for the East German FLG-5000 ILLUM and AGIT rocket series.
Bob

 

[M8owner]

Br-367p apcr

Here is something I thought I would never see even in a photo. I found a perfect BR-367P APCR 85mm projectile in the USA. It appears to have original paint and markings. Made in 1963. The red tip even shows in the manual.

 

[William49]

Hello M8owner,
you have a projectile in very good conditions.
I found this drawing to the projectile.

 

[William49]

Oh, sorry. I have seen that is already a drawing on page 1. I started with the last page.