Rotary Cannon in WW2

The P-38 would be an excellent candidate to mount a rotary Cannon.
20 mm or 23 mm rotary Cannon in powered shipboard mounts would be a good way to stop kamikazes at close range
 
The P-38 would be an excellent candidate to mount a rotary Cannon.
20 mm or 23 mm rotary Cannon in powered shipboard mounts would be a good way to stop kamikazes at close range
Sure, you could develop a brand-new super spiffy awesome weapon for those applications. Or you could just buy licences for existing, proven-to-work weapons from Oerlikon or Hispano and get the same job done for the same weight with much less cost and risk. And then put those same weapons into lots of other applications where a rotary couldn’t possibly fit.
 
The Gsh-23 is old, so what? It’s still in use and they liked it so much they designed the Gsh-30-2 (along with the Gsh-30-1) after the gsh-6-30 which I believe was their last Gatling design.
The single barrel 30 mm GSh-30-1, uses short-recoil operation, similar to the hundred year old Browning MGs. It matches 27mm Mauser in performance, yet is half as much weight.

It's cheap, and as you can burn out the barrel with a long burst, a good thing since it will be replaced far more often. It's not good for for ground support, but for a standby for when in aerial knife fighting range, you burn out the cannon, but is worth the cost, since whatever you shot at, is far more expensive to replace than the barrel.

Gunslinging is a rare event, so you have a light system that is also small in volume, unlike the miniguns. So you got room for other things, or keep the overall craft size smaller
 
Ok, I’m struggling to see the relevance of most of this. The Gsh-23 is old, so what? It’s still in use and they liked it so much they designed the Gsh-30-2 (along with the Gsh-30-1) after the gsh-6-30 which I believe was their last Gatling design.
The US is obsessed with Gatlings (and chain guns) - we know, it’s a point that has been made already.
Not sure why you cherry-pick your timeframe to ignore the 30mm Aden and the Oerlikon, as well as gloss over the various non-Gatling designs the soviets and even the US had flying. Given the premise of the thread the earlier weapons are even more relevant.
That the AMX and F1 used the M61 is good information, it makes sense for the Japanese since they are a US client but I would expect the Brazilians to be more wary of anything with ITAR restrictions given their previous experiences.

A 50 years (half a century) time-frame is not cherry picking. US (and Russians/Soviets) might or not might be obsessed with Gatlings, thing is: a) they work, and b) other people are buying them (despite having options to buy something else, like revolver cannons).
Oerlikon was neither British, nor French, nor German cannon. ADEN is a further development of the MG 213C, nowadays 70 years old. Neither ADEN nor MG 213C make for a good AA gun, unlike the predominant AO-18 or the GAU-8. The AO-18 weights as much as the twin NN-30 (AO-18 being a drop-in replacement for it), while offering more than twice the RoF and less rounds per barrel per minute (= longer barrel life; no need for water cooling, just like the GAU-8 in the Goalkeeper).

Contrary to the claimed aberation, Gatlings are very much mainstream today.

You're right. I was writing "developed the Gripen with the KCA" and messed up. :(

Viggen used KCA, Grippen used BK 27.
 
There is a couple of considerations I want to raise. Firstly size of the Weapon. In many cases the weapon in a single engine fighter is wing mounted with a Gatling weapon being to large to realistically mount and while many designs had weapons firing through the prop unless it was through the propellor hub (through a gear box arrangement like the French 520). So in many cases their would be no effective way to mount the weapon. Secondly there is weight. A Browning 303 is 10 kgs (with a 1150 RPM) and the AN/M2 .50 cal is 28 kgs (with a 750 rpm). The Minigun is 39 kgs with a 6000 rpm and the GAU 19 the 3 barrel.50 cal Gatling gun is 69 kgs (with a 2000 rpm). So kg for kg the Gatling guns deliver a high amount of fire than the conventional weapons. But as has been pointed out it takes time for the Gatling guns to spin up to speed so in a situation where targets are fleeting the increased effectiveness of the multi barrel weapon over a battery of individual guns is not as clear cut. There is also the technology. Was the tech of the late 30s and early 40s good enough to deliver such weapons as were developed in the 60s? I am not so sure.
 
The M39 revolver breech cannon would have been a potent air to air weapon in WW2. It was developed postwar however. With a rate of fire of 25 rounds a second and the reliability that the rotary breech provided two would have been sufficient fitted in the nose of a P-38 or Mosquito or etc. That would leave more room for big magazines. Hydraulically or electrically powered.

https://en.wikipedia.org/wiki/M39_cannon
1024px-F-5_IMG_6112.jpg


Cannon_M39A2.png
 
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There is a couple of considerations I want to raise. Firstly size of the Weapon. In many cases the weapon in a single engine fighter is wing mounted with a Gatling weapon being to large to realistically mount and while many designs had weapons firing through the prop unless it was through the propellor hub (through a gear box arrangement like the French 520). So in many cases their would be no effective way to mount the weapon. Secondly there is weight. A Browning 303 is 10 kgs (with a 1150 RPM) and the AN/M2 .50 cal is 28 kgs (with a 750 rpm). The Minigun is 39 kgs with a 6000 rpm and the GAU 19 the 3 barrel.50 cal Gatling gun is 69 kgs (with a 2000 rpm). So kg for kg the Gatling guns deliver a high amount of fire than the conventional weapons. But as has been pointed out it takes time for the Gatling guns to spin up to speed so in a situation where targets are fleeting the increased effectiveness of the multi barrel weapon over a battery of individual guns is not as clear cut. There is also the technology. Was the tech of the late 30s and early 40s good enough to deliver such weapons as were developed in the 60s? I am not so sure.

I don't think the metallurgy was quite there yet.
 
The M39 revolver breech cannon would have been a potent air to air weapon in WW2. It was developed postwar however. With a rate of fire of 25 rounds a second and the reliability that the rotary breech provided two would have been sufficient fitted in the nose of a P-38 or Mosquito or etc. That would leave more room for big magazines. Hydraulically or electrically powered.

The US spent the whole war screwing up the production of .60,.90 and 20mm automatic weapons.

Across the Pacific, the Japanese Army took the 1921 Browning they had a license for, and pumped it up from 7.7mm up to 13mm, then 20mm,25mm and finally arriving at 30mm in late 1944, the Ho-155

30 x 115mm
HE Projectile weight
8.3 ounce/235 g
Velocity 2350 fps/716 m/s
Rate of fire 450rpm
Weight 110 lbs/50 kg

Not as fast firing as some, projectile less powerful than others, but at 50kg, you can mount a few of them, right after WWII.

This is what the USAF should have had in place of the Mk39 when the intended target was large Soviet bombers.

The Mk39 belonged in Navy fighters rather than the Mk12, the last try at making a decent version of the Hispano404 that never worked well.
 
What specific part of the Gatling for the 1940s will be needing the metalurgy of 1960's?

The barrels and the breech. Because of the expansion out of tolerances that the firing heating would produce. However I don't know how far away the science of the 1930s and 1940s were away from building these weapons.

Do you think it was more an engineering and development problem?
 
The US spent the whole war screwing up the production of .60,.90 and 20mm automatic weapons.

Across the Pacific, the Japanese Army took the 1921 Browning they had a license for, and pumped it up from 7.7mm up to 13mm, then 20mm,25mm and finally arriving at 30mm in late 1944, the Ho-155

30 x 115mm
HE Projectile weight
8.3 ounce/235 g
Velocity 2350 fps/716 m/s
Rate of fire 450rpm
Weight 110 lbs/50 kg

Not as fast firing as some, projectile less powerful than others, but at 50kg, you can mount a few of them, right after WWII.

This is what the USAF should have had in place of the Mk39 when the intended target was large Soviet bombers.

The Mk39 belonged in Navy fighters rather than the Mk12, the last try at making a decent version of the Hispano404 that never worked well.

The USAF wasn't depending on the M39 to go after the large Soviet bombers. Thats what Genies were for. But as the weapons' trials in Korea showed it was a good weapon for going after Soviet fighters.
 
The US spent the whole war screwing up the production of .60,.90 and 20mm automatic weapons.

Across the Pacific, the Japanese Army took the 1921 Browning they had a license for, and pumped it up from 7.7mm up to 13mm, then 20mm,25mm and finally arriving at 30mm in late 1944, the Ho-155

30 x 115mm
HE Projectile weight
8.3 ounce/235 g
Velocity 2350 fps/716 m/s
Rate of fire 450rpm
Weight 110 lbs/50 kg

Not as fast firing as some, projectile less powerful than others, but at 50kg, you can mount a few of them, right after WWII.

This is what the USAF should have had in place of the Mk39 when the intended target was large Soviet bombers.

The Mk39 belonged in Navy fighters rather than the Mk12, the last try at making a decent version of the Hispano404 that never worked well.
Or just listened to the British?
 
The M39 revolver breech cannon would have been a potent air to air weapon in WW2. It was developed postwar however. With a rate of fire of 25 rounds a second and the reliability that the rotary breech provided two would have been sufficient fitted in the nose of a P-38 or Mosquito or etc. That would leave more room for big magazines. Hydraulically or electrically powered.

https://en.wikipedia.org/wiki/M39_cannon
1024px-F-5_IMG_6112.jpg


Cannon_M39A2.png
Yes something like the 30mm Aden cannon would have been amazing. But again the development of revolver cannon was dependent on the trials and tribulations of cannon development during WW2. Went to Tangmere museum earlier in the year and they had several ‘training’ Aden guns with cutaways etc as well as the entire belly pack from an early Lightning with 4 guns.
 
This thread seems to focus on 2 applications for the gatling type weapon, shipboard AA and aerial use. Let's skip shipboard. I think the use of this type of weapon in aircraft needs to wait for bigger, more powerful jet powered aircraft. A Gatling gun is like a torpedo, not buttoned up in a nice linearly designed package like a torp, but it's big and bulky, and has its own needs for a separate power source. Too big for a single engine, not worthwhile for anything big enough to tote it around.
 
This thread seems to focus on 2 applications for the gatling type weapon, shipboard AA and aerial use. Let's skip shipboard. I think the use of this type of weapon in aircraft needs to wait for bigger, more powerful jet powered aircraft. A Gatling gun is like a torpedo, not buttoned up in a nice linearly designed package like a torp, but it's big and bulky, and has its own needs for a separate power source. Too big for a single engine, not worthwhile for anything big enough to tote it around.

One of the Gatling gun’s problems for air combat is spin up time. It takes a second and that’s enough for the opportunity to be lost. Soviet Gatling guns experimented with using cartridge detonation to start up spin. Ultimately they had more success with Gast guns. It was light weight and simple, was almost as fast as Gatlings and faster than revolver cannons.

Gast guns were developed by the Germans in late WWI. For some reason it was forgotten until the Soviets got interested in the 1950s.
 
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I was thinking more of ship busting and ground attack than air to air combat but this has been very interesting and enlightening .
 
The barrels and the breech. Because of the expansion out of tolerances that the firing heating would produce. However I don't know how far away the science of the 1930s and 1940s were away from building these weapons.

Do you think it was more an engineering and development problem?

I think it was one of those 'why we didn't recall this earlier' problems.
A 6-barreled 20 mm cannon that fires at 4800 rounds per minute means that each barrel will be firing at 800 rd/min - same as most of ww2 20 mm cannons.

One of the Gatling gun’s problems for air combat is spin up time. It takes a second and that’s enough for the opportunity to be lost. Soviet Gatling guns experimented with using cartridge detonation to start up spin. Ultimately they had more success with Gast guns. It was light weight and simple, was almost as fast as Gatlings and faster than revolver cannons.

Gast guns were developed by the Germans in late WWI. For some reason it was forgotten until the Soviets got interested in the 1950s.

IIRC, during the BoB pilots were instructed to fire 2-second bursts. So even if one second of firing time is done on half the normal RoF, it will still fire 40+80=120 rounds for the two seconds for the hypothetical 20mm ww2 Gatling from the start of this post.
Soviets have made 3 Gatlings, and 2 Gast-type guns. While we know that big Soviet Gatlings were not much of a success when installed on aricraft (apart from the MiG-31 and Mi-24), Soviets/Russians went full bore with 30mm gatling for ship defense in singe and twin installations, and so did the NATO with 20 and 30 mm Gatlings.
 
Ammunition weight and accuracy also come into play. Each 20x102 round weighs about 0.32kg if memory serves, so even with the XM301 (later experimental tri-barrel 20mm cannon) the weight of ammunition quickly added up. And while 20mmworked well, the Mk108 of Germany in 30mm was devastating...under very specific circumstances. The 'pneumatic jackhammer' experienced rapid ballistic drop-off, but when it did hit it was devastating. Various powers worked to make much lighter weight versions of 37mm and 75mm artillery/anti-tank gun pieces as well. For extra kicks, you could take a Hotchkiss rotary artillery piece and 'modernize' it somewhat for 37mm, 47mm, or even 57mm though the higher you go the less useful it likely becomes.

https://www.forgottenweapons.com/hotchkiss-revolving-cannon/
https://en.wikipedia.org/wiki/75_mm_Gun_M2/M3/M6
https://en.wikipedia.org/wiki/XM301 (Designed much later for the RAH-66 project but dang look how far we've come in weight reduction)

For extra specs on existent rotary cannons:

http://u-fr.blogspot.com/2011/08/aircraft-cannon-data.html
 
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