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Russian 37mm (61-K AA / NS-37 / N-37)

I

Irod7

Well-Known Member
Hello guys,

I`ve recently wrapped my head around russian 37mm ammo and oddly enough it seems that this is not very well documented on the internet.
My main question here is wether or not the ammunition uses the same bodies and has different indexes depending on what casing it is being fitted to.

For the 1939 61-K AA gun, we have


OR-167 without tracer, using MG-8 fuzes
OR-167 with tracer, using MG-37 or MG-37M fuzes (until 1967 it used the "no.5" tracer, since 1968 it used "no.9" tracer)
OR-167N with tracer, using B-37 fuzes
OZR-167 with (?) tracer, using MG-37 fuzes
BR-167 with tracer, no fuze (solid shot)

For the NS-37 air cannon we have

OZT with tracer , using ?? fuzes (probably MG-37)
BZT with tracer, no fuze (solid shot)

For the N-37 air cannon we have

OFZ without tracer, using B-37 fuze
OZT with tracer, using MG-37 or A-37 or A-37u (depending on year of production)
BZT with tracer, no fuze (solid shot)

My question here is, can we assume that OR-167 = OZT and BR-167 = BZT? Meaning that the same projectile receives a different index depending on what case it is being mated with, but essentially it is the same projectile? I have not been able to confirm this through the documents available to me.

Thanks in advance.
 
37mm 61-K (AZP-39 )

OR-167N :
(drawing russian manual 1981)

Snímek obrazovky z 2026-03-11 13-30-13.png1773232459641.png
1773235109960.png1773235148362.png
1773235198581.png

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37mm N-37
OFZ
OZT
1773232823688.jpeg
1773234347972.png
1773234862924.png
37mm N-37
SSSR lizenc > ČSSR ..
(Tech doc.)

1773233135610.png

Source- NI.
1773235529030.jpeg
Akon
 
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Hi Irod7
You have to confirm or refute your own working hypothesis yourself. I won't help you with that :)
I think you have the documents on the table.
Akon
 
Thanks guys for the input!

It seems that, this time, i come with the answer as well, and it comes from Christian Koll`s book "Soviet Cannon". However, the answer comes in a rather indirect form.

On page 346, when describing ammunition of the N-37, he says
The BZT projectile is identical to the armour piercing tracer projectile of the NS-37
Click to expand...
Later, on page 361, when describing the ammunition of the NS-37, he says
The new BZT projectile was taken from the 37mm M1939 anti-aircraft gun without any changes
Click to expand...

For the HE shells, we have the same clues.
On page 346, when describing ammunition of the N-37, we have :
The main service projectile in this calibre is the OZT shell, which was taken from the NS-37 ammunition without any changes.
Click to expand...
Later, on page 361, when describing ammunition of the NS-37 , we have:
The OZT projectile was apparently introduced somewhat later than the OZ. It is identical to the OR-167 projectile of the 37mm anti-aircraft gun M1939
Click to expand...

I would have two things to point out though.
The ammunition for N-37 suffered some modifications : the addition of transverse radial holes (pressure balance holes), three for the OZT and two for the BZT ammunition (change introduced in 1949), and of course the upgrading of the fuzes according to the new speeds of the aircraft (also in 1949), and the change from No.5 to No.9 tracers in 1968.
Secondly, the BZT is named rather in a strange (incorrect) way according to soviet doctrine, since it does not have any separate incendiary compound, and this fact is pointed out by Koll as well.
 
Such a thought: after I looked through several sources that describe it more thoroughly than Mr. Koll
....

Let's turn the question around. So where did the 37x252SR cartridge for the 61-K AA gun come from, which he so simply points to as the source ... which was being passed around among the designers .


If we take it the other way around, where did the 37x252SR cartridge come from? Gradually, we will come to the fact that the cartridge was born in the Design Bureau OKB-2 Koloma. It was in connection with the development of the Sh-37 aircraft cannon.How did the Sh-37 cannon get to this office? It was certainly a decision of the authorities (Spitalny worked on many projects and the state wanted to have the results achieved on some of them as a priority) ..... that is what happened because the Sh-37 aircraft cannon of the designer Shpitalny old 37x252SR , new project 37x198 ... was moved to this office OKB-2 + in conjunction with the ZIK production plant, it was still modified, including changes to the cartridge.Originally, the Spitalny cannon, before modifications in OKB-2 in cooperation with the ZIK plant, had a 37x198 cartridge, or rather a 37x198R cartridge (with a rim). The matter is complicated by the fact that there were actually two 37x198 cartridges: one designed by Spitalny and the other designed by Nudelman for the N-37 project for the 37x198 cartridge - they differed in the design of the bottom. Spitalny had a rim, Nudelman did not. . There was also a different distance for crimping the cartridge case on the shel ....The Spitalny cartridge was equipped with an armor-piercing bullet with a tracer of a different design than the later used BZT-167 shell. The OZT projectile had the same concept as we know. It can be said that Nudelman won the design duel in the 37mm caliber ....

This is despite the fact that the Sh-37 cannon had long been flying and firing in aircraft (it had been officially introduced into service), and on the other hand, the N-37 project was still in its infancy...


So back to the 37x252SR cartridge ....
The concept of the Sh-37 Spitalni cannon was used in Plant No. 8 Kaliningrad (Sverdlovsk ), which specialized in artillery weapons, specifically anti-aircraft guns. Russian sources state that it was an adaptation (if you want a copy of the 25mm Bofors in 37mm caliber). The shape of the cartridge case (or rather its bottom corresponds to it. This created a new cannon under the designation ZIK-37 - later introduced under the designation Interal K-100 (mil. disign 61-K), designer Longinov (director of the design office) the start of the project for the new cannon was in 1938 and in 1939 it was introduced into service (an unusually short period from design, testing to introduction. This is the birth of the 37x252SR cartridge with the BZT-37 bullet ... So it is probably possible to search for details in the ZIK factory ... in Kaliningrad.

We certainly don't know much about many things, it is certain that the strength of the aforementioned book is not the quality of the timeline and details of the development of the cannon and its ammunition. On the contrary, the strength is the quality of the photographs of the actual pieces. ...That's my opinion, you can have the same, similar or opposite, that's for sure.
Akon
 
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sgdbdr said:
Great references AKON_ and microplastic !

Are those books available online ? If so, could you provide information ?

Cheers,

S.
Click to expand...
Yes, you can say: everything is on the Internet (or will be there someday).... however, the last two photos are not online. Technical documentation is not suitable for such a publication. I found everything else in 5 minutes just by entering keywords in Russian, not in English. Then you need to know the context and then you know what to look for. References are opinions and opinions, as far as I know, can be true, or partially or not at all. It is a duel of interpretation of what we see with what really happened...
Akon
 
1773587981910.jpeg
There is a lot I don't know about it, for example, this type of bullet is very common. It is in the original in a 37x198 cartridge. Here in the picture it is outside the cartridge (unfired) and there are photos of it fired. The date on the shel is 1941...

Note, among other things, the different spacing of the grooves for crimping the cartridge .
Akon
.
 
sgdbdr said:
I'm interested in the old russian and german manuals
Click to expand...
I don't know anyone who doesn't want military technical regulations (except golfers) :)
By the way, are we talking about a financial investment on your part or that you want it without the cost and effort?
I'm asking just to make sure everyone is clear about what it's about?
Akon
 
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