Slostin rotary machine gun, 1936

[Kiltonge]

New to me:

Around 1936, designer Slostin developed a prototype rotary machine gun in 7.62x54R. This weapon had a rotary cluster of 8 barrels a-la Gatling, but unlike most such systems it was self-powered, using gas pistons attached to each barrel. Development of this “squall-firing gun” (in contemporary Russian terminology) with rates of fire reaching 6-8 thousands of rounds per minute, continued up until 1944 or 1945.

http://sadefensejournal.com/wp/?p=1439

Image here without any details

http://guns.wikia.com/wiki/File:SlostinGun.jpg

Apparently he then went on to design a rotary 14.5mm beast!

 

[Tony Williams]

The Soviets produced some unconventional MG designs of astonishing performance: apparently the result of setting up an engineering college devoted entirely to training automatic weapon designers. They were constantly pushing the boundaries of what was technically possible. I suspect that this one, like others, ran into the problem that no-one could think of a good use for it...

 

[Avimimus]

The mobile mounting is interesting. I'd be tempted to design an aircraft around it. Jamming might be an issue if you are investing that much in one weapon though.

Mr. Williams - Does that explain the overall success in aviation cannons that the Soviet Union had?

Even into the 1980s many Soviet guns are reportedly more compact, have higher rates of fire, or weigh less than their western counterparts. One gets the impression that the ADEN, DEFA and M61 all lagged behind their conterparts (GSh-301, and the admittedly troubled GSh-6-23, come to mind). I've always wondered why. Could it be traced back to the 1930s or were there other factors?

 

[lastdingo]

Ever sine the B-20 the Soviets seemed to have dispensed with durability in favour of less weight.

 

[marauder2048]

The Soviets produced some unconventional MG designs of astonishing performance: apparently the result of setting up an engineering college devoted entirely to training automatic weapon designers. They were constantly pushing the boundaries of what was technically possible. I suspect that this one, like others, ran into the problem that no-one could think of a good use for it...

What exactly is unconventional about this design? It's a gas piston version of Gatling's own Direct Impingement design of 1895.

Soviet autocannon design seems to have improved dramatically after they received large numbers of lend lease M1 and M4/M10 37mm autocannons.

 

[Avimimus]

Ever sine the B-20 the Soviets seemed to have dispensed with durability in favour of less weight.

I'm not sure if this is the case. For instance the Ultra-ShKAS sought tremendous performance but had reliability issues.

Whereas the, B-20 was essentially a scaled up Berezin UB heavy machine gun - a weapon which had a number of design features that sought to increase reliability over existing designs.

 

[Tony Williams]

Mr. Williams - Does that explain the overall success in aviation cannons that the Soviet Union had?

I don't have any proof of the link, but I suspect that it does.

Even into the 1980s many Soviet guns are reportedly more compact, have higher rates of fire, or weigh less than their western counterparts. One gets the impression that the ADEN, DEFA and M61 all lagged behind their conterparts (GSh-301, and the admittedly troubled GSh-6-23, come to mind). I've always wondered why. Could it be traced back to the 1930s or were there other factors?

The Aden/DEFA, M39 and M61 were all 1950s designs. Contemporary Soviet guns were the 30mm NR-30 followed by the 23mm GSh-23. These were both light and compact compared with Western guns (partly because they accepted a shorter gun life, calculating that in wartime the aircraft that carried them would have a short life anyway).

The 1970s series of aircraft guns (GSh-6-23, GSh-6-30, GSh-30 and GSh-301) were contemporary with the Mauser BK 27. They are also very light and fast-firing: the GSh-301 has approx the same rate of fire as the BK 27 and fires ammo just as powerful, but weighs only about half as much; the twin-barrel GSh-30 weighs about the same as the BK 27, but fires almost twice as fast; the GSh-6-23 weighs less than the M61 but fires at 9,000 rpm.

The USSR had a long tradition of designing impressive automatic cannon, with several competing design organisations keeping each other on their toes. After John Browning the US had no-one in that league, until German engineers arrived after WW2.

 

[Tony Williams]

What exactly is unconventional about this design? It's a gas piston version of Gatling's own Direct Impingement design of 1895.

Which makes the mechanism unique. How many other contemporary gas-piston driven rotary-barrel guns can you name?

Soviet autocannon design seems to have improved dramatically after they received large numbers of lend lease M1 and M4/M10 37mm autocannons.

You have got to be kidding. The Soviet 37mm M1939 AA gun was based on the Bofors gun. Lend-Lease started in 1941, two years later. The US 37mm M1 AA gun was considered inferior to the Bofors, even by the US.

The Soviet NS-37 aircraft cannon was designed and made in 1941. It had a short-recoil mechanism rather than the long-recoil US M4/M10. The 37x198 ammo was more than twice as powerful as the the 37x145R ammo used by the M4/M10, yet the gun fired almost twice as fast (250 rpm rather than 150 rpm) while weighing only c.60% more. It was also much slimmer, making it easier to fit into aircraft. It was a vastly superior design.

 

[Rickshaw]

After John Browning the US had no-one in that league, until German engineers arrived after WW2.

Interesting comment. What designs did these German engineers work on? The American attempts at revolver cannon weren't particularly successful and I can't imagine German engineering contributing much to rotary cannon designs.

 

[marauder2048]

What exactly is unconventional about this design? It's a gas piston version of Gatling's own Direct Impingement design of 1895.

Which makes the mechanism unique. How many other contemporary gas-piston driven rotary-barrel guns can you name?

Nice weasel words. There were no contemporary electric powered gatling guns either but no one claims that their subsequent
re-invention resulted in designs that were "unique" or "unconventional."

Soviet autocannon design seems to have improved dramatically after they received large numbers of lend lease M1 and M4/M10 37mm autocannons.

You have got to be kidding. The Soviet 37mm M1939 AA gun was based on the Bofors gun. Lend-Lease started in 1941, two years later. The US 37mm M1 AA gun was considered inferior to the Bofors, even by the US.

The Soviet NS-37 aircraft cannon was designed and made in 1941. It had a short-recoil mechanism rather than the long-recoil US M4/M10. The 37x198 ammo was more than twice as powerful as the the 37x145R ammo used by the M4/M10, yet the gun fired almost twice as fast (250 rpm rather than 150 rpm) while weighing only c.60% more. It was also much slimmer, making it easier to fit into aircraft. It was a vastly superior design.

The NS-37 was a failure as a design and rather quickly removed from service; Savage recoil, unreliability and poor accuracy. Comparing uninstalled cyclic rates is a bit like remarking on uninstalled engine thrust figures.

The US 37mm M1 gun gave the Russians something they desperately needed; a reliable, accurate medium caliber autocannon that could be vehicle mounted. The viability and utility of towed medium caliber AA guns was very much in doubt by 1943.

 

[marauder2048]

After John Browning the US had no-one in that league, until German engineers arrived after WW2.

Interesting comment. What designs did these German engineers work on? The American attempts at revolver cannon weren't particularly successful and I can't imagine German engineering contributing much to rotary cannon designs.

They had a pretty negligible impact. The big postwar developments were externally powered autocannon: chain guns (Price and Stoner) and vulcan-style gatling guns.

 

[Tony Williams]

After John Browning the US had no-one in that league, until German engineers arrived after WW2.

Interesting comment. What designs did these German engineers work on? The American attempts at revolver cannon weren't particularly successful and I can't imagine German engineering contributing much to rotary cannon designs.

The M39 revolver cannon was the USAF's standard gun from the mid-1950s until the M61 took over during the 1960s, and it remains in service to this day in the F-5 fighters which are still around in some numbers. German engineers who had worked on the Mauser MG 213C revolver cannon were extensively involved in the project.

I hadn't thought that German engineers had anything to do with the rotary gun programme, until I read not long ago that at least one of their gun engineers went to the US to work on the M61 prototypes. I'm trying to recall in which book I read this and who the guy was, but struggling at the moment...

 

[Tony Williams]

Nice weasel words. There were no contemporary electric powered gatling guns either but no one claims that their subsequent re-invention resulted in designs that were "unique" or "unconventional."

You have an odd definition of "unconventional". My dictionary says: "Not adhering to convention; out of the ordinary." The convention for automatic weapons at the time had for several decades been for single-barrel guns. In fact, there were no other types in use anywhere in the 1930s AFAIK. Therefore, any type of new gun design with a different operating system was certainly unconventional, and in the Slostin was unique because no-one had combined gas-piston operation with a rotary multi-barrel gun before.

The NS-37 was a failure as a design and rather quickly removed from service; Savage recoil, unreliability and poor accuracy. Comparing uninstalled cyclic rates is a bit like remarking on uninstalled engine thrust figures.

Certainly the recoil was heavy - an inevitable product of very powerful ammunition fired at a high rate from a relatively light gun. But once the installation was perfected, over 2,700 Yak-9T armed with it saw service up to the end of the war, and this aircraft variant was highly regarded and "...soon became one of the principal Soviet fighters" (Yefim & Gordon, Soviet Combat Aircraft of the Second World War).

The US 37mm M1 gun gave the Russians something they desperately needed; a reliable, accurate medium caliber autocannon that could be vehicle mounted.

The Soviets already had this in the M39, which was "found to be very reliable and simple to operate and maintain" (Koll, Soviet Cannon). Some 2,600 of these 37mm AA guns guns were made in 1941, and just under 17,000 by the end of the war.

The one site I've found which lists the numbers and types of Lend-Lease equipment sent to the USSR states that only 340 37mm AA guns were sent (but 5,400 40mm Bofors guns).

So deliveries of the 37mm M1 were negligible and it didn't provide any capability that the Soviets didn't already have.

(Link removed, see next post )

 

[TomS]

Tony, I'd really advise not linking to vnnforum, even if it is the only site with your data. The Vanguard News Network is a forum explicitly for white supremacists.

 

[J.A.W.]

Is the listed Lend-Lease data verifiably accurate?

Or - has the site been demonstrably shown to deliberately falsify/promulgate known to be incorrect - statistical figures?

Valid data sets or not, is the real question - regardless of perceived political/ideological concerns.

This has long been an issue for research into Soviet era matters.

 

[marauder2048]

After John Browning the US had no-one in that league, until German engineers arrived after WW2.

Interesting comment. What designs did these German engineers work on? The American attempts at revolver cannon weren't particularly successful and I can't imagine German engineering contributing much to rotary cannon designs.

The M39 revolver cannon was the USAF's standard gun from the mid-1950s until the M61 took over during the 1960s, and it remains in service to this day in the F-5 fighters which are still around in some numbers. German engineers who had worked on the Mauser MG 213C revolver cannon were extensively involved in the project.

I hadn't thought that German engineers had anything to do with the rotary gun programme, until I read not long ago that at least one of their gun engineers went to the US to work on the M61 prototypes. I'm trying to recall in which book I read this and who the guy was, but struggling at the moment...

So a revolver cannon that had an incredibly short active service life aside from on a fighter the USAF deemed unfit for front-line service. I'd say that qualifies as negligible.

 

[Tony Williams]

Tony, I'd really advise not linking to vnnforum, even if it is the only site with your data. The Vanguard News Network is a forum explicitly for white supremacists.

Thanks for the warning; I wasn't aware of that, I just put in a search for Lend-Lease 37mm equipment to the USSR and it was the only one with the data.

 

[marauder2048]

Nice weasel words. There were no contemporary electric powered gatling guns either but no one claims that their subsequent re-invention resulted in designs that were "unique" or "unconventional."

You have an odd definition of "unconventional". My dictionary says: "Not adhering to convention; out of the ordinary." The convention for automatic weapons at the time had for several decades been for single-barrel guns. In fact, there were no other types in use anywhere in the 1930s AFAIK. Therefore, any type of new gun design with a different operating system was certainly unconventional, and in the Slostin was unique because no-one had combined gas-piston operation with a rotary multi-barrel gun before.

The NS-37 was a failure as a design and rather quickly removed from service; Savage recoil, unreliability and poor accuracy. Comparing uninstalled cyclic rates is a bit like remarking on uninstalled engine thrust figures.

Certainly the recoil was heavy - an inevitable product of very powerful ammunition fired at a high rate from a relatively light gun. But once the installation was perfected, over 2,700 Yak-9T armed with it saw service up to the end of the war, and this aircraft variant was highly regarded and "...soon became one of the principal Soviet fighters" (Yefim & Gordon, Soviet Combat Aircraft of the Second World War).

The US 37mm M1 gun gave the Russians something they desperately needed; a reliable, accurate medium caliber autocannon that could be vehicle mounted.

The Soviets already had this in the M39, which was "found to be very reliable and simple to operate and maintain" (Koll, Soviet Cannon). Some 2,600 of these 37mm AA guns guns were made in 1941, and just under 17,000 by the end of the war.

The one site I've found which lists the numbers and types of Lend-Lease equipment sent to the USSR (http://vnnforum.com/showthread.php?t=136210) states that only 340 37mm AA guns were sent (but 5,400 40mm Bofors guns).

So deliveries of the 37mm M1 were negligible and it didn't provide any capability that the Soviets didn't already have.

There were patents for gas-operated gatling type guns from Gatling's direct impingement patent in 1895 all the way to the 1930's including gas-piston operation of gatling guns. The convention at Slotsin's time was gas piston for the operation of automatic weapons. And since the prior art included gas operation of all manner for gatling type guns there was nothing unique about Slotsin's design either.


Slotsin's design may very well have attained high rates of fire and had it been pneumatically or hydraulically operated it would have
been unconventional and unique since there was no prior art that explored those options.


The Yak-9T and its uber-cannon were dropped from front-line service after 1945; the P-63 and its inferior armament were still in front-line service well into the Korean War.

Even a small number of SPAAGs can have a big impact as evidenced by the US experience in North Africa.

 

[Tony Williams]

The M39 revolver cannon was the USAF's standard gun from the mid-1950s until the M61 took over during the 1960s, and it remains in service to this day in the F-5 fighters which are still around in some numbers. German engineers who had worked on the Mauser MG 213C revolver cannon were extensively involved in the project.

So a revolver cannon that had an incredibly short active service life aside from on a fighter the USAF deemed unfit for front-line service. I'd say that qualifies as negligible.

I did not express an opinion on its importance, I merely provided information. Your opinion that it is a "negligible" weapon should be assessed in the light of the fact that over 35,000 M39 cannon were made (http://www.hill.af.mil/library/factsheets/factsheet.asp?id=5700).

 

[Tony Williams]

There were patents for gas-operated gatling type guns from Gatling's direct impingement patent in 1895 all the way to the 1930's including gas-piston operation of gatling guns. The convention at Slotsin's time was gas piston for the operation of automatic weapons. And since the prior art included gas operation of all manner for gatling type guns there was nothing unique about Slotsin's design either.

Slotsin's design may very well have attained high rates of fire and had it been pneumatically or hydraulically operated it would have been unconventional and unique since there was no prior art that explored those options.

"Unconventional" does not mean "nobody has ever thought of it before"; it means "it isn't what's usually done". Almost every element in machine gun design was explored over a century ago; what is unique about the Slostin is not that any particular aspect of it was original, but its combination of features - and the fact that it was made and tested rather than just an idea that someone had.

The Yak-9T and its uber-cannon were dropped from front-line service after 1945; the P-63 and its inferior armament were still in front-line service well into the Korean War.

Which simply indicates that it was a more modern and advanced aircraft than the Yak-9.

Even a small number of SPAAGs can have a big impact as evidenced by the US experience in North Africa.

Tell me, do you have any source which supports your contention that the 340 37mm M1 AA guns supplied to the USSR were of vital importance in providing a capability that the 17,000 Soviet M39 cannon could not?

 

[Rickshaw]

After John Browning the US had no-one in that league, until German engineers arrived after WW2.

Interesting comment. What designs did these German engineers work on? The American attempts at revolver cannon weren't particularly successful and I can't imagine German engineering contributing much to rotary cannon designs.

The M39 revolver cannon was the USAF's standard gun from the mid-1950s until the M61 took over during the 1960s, and it remains in service to this day in the F-5 fighters which are still around in some numbers. German engineers who had worked on the Mauser MG 213C revolver cannon were extensively involved in the project.

Fair enough, I'd forgotten about the M39, although, I will point out in US service it wasn't very successful it was only carried on four other types of aircraft in US server (F-86H, F-100, F-101A and F-101C). While large numbers might have been produced for foreign us, my point was really about success in US service.

I hadn't thought that German engineers had anything to do with the rotary gun programme, until I read not long ago that at least one of their gun engineers went to the US to work on the M61 prototypes. I'm trying to recall in which book I read this and who the guy was, but struggling at the moment...

Excellent. Well, I've learnt something new today. Thank you!

 

[Rickshaw]

The Yak-9T and its uber-cannon were dropped from front-line service after 1945; the P-63 and its inferior armament were still in front-line service well into the Korean War.

The Yak-9T wasn't dropped because of any failure of it's weapon, it was dropped because it's airframe was wood and had a short life in the harsh Russian winters. The P-63 OTOH was metal construction and so it was retained in service. Interestingly the Lavochkin series of radial engined fighters changed to metal construction and outlasted the P-63 in Soviet service.

 

[Avimimus]

That makes sense Kadija Man - except that the Yaks also changed to metal frames/wings and then all metal construction by the end of the war (Yak-9U and Yak-9P).

Both the Yak-9P and the P-63 were encountered in the Korean war - a time when jets had clearly overtaken piston engined designs. I think that no intelligent conclusion can be drawn from which were retired first in the 1950s... so, they all basically lasted until the very end of piston engined fighter aircraft.

However, I will make one additional point - if Soviet produced automatic cannons were so flawed: Why were they constantly developing new ones, and why did they continue to prefer cannons during the 1950s (when the U.S. was still hesitating about replacing its machine guns with heavier weapons)?

 

[Tony Williams]

However, I will make one additional point - if Soviet produced automatic cannons were so flawed: Why were they constantly developing new ones, and why did they continue to prefer cannons during the 1950s (when the U.S. was still hesitating about replacing its machine guns with heavier weapons)?

I think that by the 1950s the USAF had learned from its Korean War experience that the something more powerful than the .50 BMG was needed to down jets (the USN had switched to 20mm cannon somewhat earlier). The first prototypes of the M39 were rushed into action at the end of the war in Project GunVal (gun evaluation) and entered service as soon as they were ready. The older-generation 20mm M24 cannon was also used by the USAF, mainly in bomber defence.

However, the US never again used anything bigger than 20mm calibre in a fighter, despite testing various alternatives in 25mm and 30mm. Only the A-10 "tank buster" carried a powerful 30mm gun for ground attack, and the USMC's Harriers carried larger calibre cannon also. Meanwhile, both the West Europeans and the Soviets adopted 30mm cannon as standard for fighters in the 1950s.

 

[J.A.W.]

Indeed, the whole cannon armed aircraft deal is fraught with national pride/presumed VS - as delivered efficacy issues.
The Brits, to their credit were never shy about the 'not invented here' factor..

& so, the exemplar exists of the potent standard fit of 4 x 20mm H-S cannon in new RAF fighters from 1940..