2S38 Derivatsiya-PVO 57-mm SPAAG

DerWolf wrote:57 mm anti-aircraft gun would be very effective because projectiles and guns, different from missiles, can not be jammed. Basically only one round of 57 mm shell would shoot down an aircraft.

Guns also require to be guided you know . Times when Eye Mk1 only guidance was a thing are gone. Today if you want to hit something you need night optical channel, radar guidance, laser designation, automatic tracking... Some of these are passive, some are active and have emmisions that can either be jammed or detected/tracked.

One can shoot it down... if it hits the target .

Militarov wrote:

DerWolf wrote:57 mm anti-aircraft gun would be very effective because projectiles and guns, different from missiles, can not be jammed. Basically only one round of 57 mm shell would shoot down an aircraft.

Guns also require to be guided you know . Times when Eye Mk1 only guidance was a thing are gone. Today if you want to hit something you need night optical channel, radar guidance, laser designation, automatic tracking... Some of these are passive, some are active and have emmisions that can either be jammed or detected/tracked.

One can shoot it down... if it hits the target .

Yes of course the shell should be guided and the passive form seems the most realible guidance system rather the active one.

Militarov wrote:
Times when Eye Mk1 only guidance was a thing are gone.

I still trust on this kind of guidance by day.

Militarov wrote:
Today if you want to hit something you need night optical channel, radar guidance, laser designation, automatic tracking... Some of these are passive, some are active and have emmisions that can either be jammed or detected/tracked.

Now it exists passive sensors that detect, and guide the gun, without the aircraft could detect. In fact it is always game of cat and mouse. But since 1940, the effectiveness of bombing is rather pitiable everywhere, in nearly all conflict. It proves that that anti air defense is still effective. The new laser embedded with this new AU-220M 57 mm could be useful. For example the Mig-35 does need radar to detect every stealth airplane. At Mach 1.4 the friction on the air create an elevation of temperature, and this elevation could be detected at several dozens of KM around by sensors. IRST -called OLS- on Mig-35, and sensors inside AU-220M.

I tend to think that Russia would adopt this weapon only in a configuration that improves significantly the ZSU-23-4 in all the features of the verteran predeccessor.

The minimum conditions that I would see for Russia to consider to adopt this weapon would be:

- To have at least a 57-4 configuration.
- To be mounted in one of the new Russian armoured platforms (Armata, Kurganets, Bumerang or BMD-4M).

eehnie wrote:I tend to think that Russia would adopt this weapon only in a configuration that improves significantly the ZSU-23-4 in all the features of the verteran predeccessor.

The minimum conditions that I would see for Russia to consider to adopt this weapon would be:

- To have at least a 57-4 configuration.
- To be mounted in one of the new Russian armoured platforms (Armata, Kurganets, Bumerang or BMD-4M).

57-4 aint happening for sure.

If you went for unguided shells then more barrels would put more shells in the air faster so increase the chance of a hit, but the enormous weight and size of a vehicle with 4 x 57mm guns would be a problem, plus all the ammo you would need to carry to even have a chance to bring down an aircraft would be enormous.

With guided shells then the rate of fire is no longer critical, so one barrel is actually better as it is lighter and simpler and frees up more space for more ammo.

I suspect if successful the 57mm calibre will replace both the 30mm in the anti aircraft role (ie Tunguska) and in the anti armour role for IFVs (ie BMP-2/-3), and will make the extra HE calibre (BMP-1/-3) redundant too.

At sea I think a 57mm gun would offer better CIWS performance and also be a more useful multirole weapon for light and medium and heavy vessels.

Will be interesting to see what they do with light APCs... at the moment an APC like a BTR-80 and BTR-80A has either a 14.5mm HMG or a 30mm cannon... if they traded the 30mm cannon for a twin barrel 23mm cannon, or even a single barrel 23mm cannon based on the KPV HMG it would be interesting to see whether they stayed with cannon/HMG or if they went for a dual calibre system with 23 x 115mm and 14.5 x 114mm weapons...

I think either combination with a rifle calibre MG and a 40mm grenade launcher would be an excellent selection enabling a range of targets to be effectively engaged...

A 57-4 configuration would be able to operate both, guided and unguided ammunition. I understand that this configuration would be very helpful to reach fire saturation with unguided ammunition in units with several vehicles of this type, while also would be able to shot smaller amounts of guided ammunition. I do not think that a salve of 4 guided projectiles would be too much to assure strong damage, they are small, but even this kind of system would have a chance to fire only one, two or three, this is easy to do.

About the size, if necessary there is the chance to go to the Armata platform, but if possible I would prefer a smaller platform, I would not rule out the Kurganets platform. In the pictures with 57-1 configuration the turret looks small for the armoured vehicle.

eehnie wrote:A 57-4 configuration would be able to operate both, guided and unguided ammunition. I understand that this configuration would be very helpful to reach fire saturation with unguided ammunition in units with several vehicles of this type, while also would be able to shot smaller amounts of guided ammunition. I do not think that a salve of 4 guided projectiles would be too much to assure strong damage, they are small, but even this kind of system would have a chance to fire only one, two or three, this is easy to do.

About the size, if necessary there is the chance to go to the Armata platform, but if possible I would prefer a smaller platform, I would not rule out the Kurganets platform. In the pictures with 57-1 configuration the turret looks small for the armoured vehicle.

in low atmosphere nothing goes past mach 1,5-2.- 0,5km/s... not even supersonic missiles or fighters. and they would glow allot in IR.

if you detect at 12-15km you have plenty of time to respond at least 10 sec. with 2 rd/sec , thats 30 guided rounds incoming to interception at 6km. major improvement was reaction time and interception balistics solution tnx to quick computers. it would take lots of time but today its very fast.

Rmf wrote:

eehnie wrote:A 57-4 configuration would be able to operate both, guided and unguided ammunition. I understand that this configuration would be very helpful to reach fire saturation with unguided ammunition in units with several vehicles of this type, while also would be able to shot smaller amounts of guided ammunition. I do not think that a salve of 4 guided projectiles would be too much to assure strong damage, they are small, but even this kind of system would have a chance to fire only one, two or three, this is easy to do.

About the size, if necessary there is the chance to go to the Armata platform, but if possible I would prefer a smaller platform, I would not rule out the Kurganets platform. In the pictures with 57-1 configuration the turret looks small for the armoured vehicle.

in low atmosphere nothing goes past mach 1,5-2.- 0,5km/s... not even supersonic missiles or fighters. and they would glow allot in IR.

if you detect at 12-15km you have plenty of time to respond at least 10 sec. with 2 rd/sec , thats 30 guided rounds incoming to interception at 6km. major improvement was reaction time and interception balistics solution tnx to quick computers. it would take lots of time but today its very fast.

In other countries it is possible to see attacks of low number of units, but in the case of Russia, the likely attacks would be massive attacks with dozens or even hundreds of units in fronts of limited size. In the case of Russia it would be possible to face situations where the time of reaction is significantly lower and fire saturation can be interesting as defense strategy.

If the goal is to create a successor of the SA-22 Pantsir I think the low mark would be a 57-2 configuration, but if the goal is to go to a weapon with smaller number of missiles in the mold of the ZSU-23-4 or the ZSU-57-2, I think the 57-4 configuration would be the minimum required.

then produce more units.
anyway 2-57mm gunns ,and 12 missiles would be really powerfull.

Rmf wrote:then produce more units.
anyway 2-57mm gunns ,and 12 missiles would be really  powerfull.

To produce more units is far more expensive.

Actually the whole driver behind the Tunguska and Pantsir is that the sensors are expensive, but the missiles are cheap simple command guided high speed weapons with high PK.

Missiles and guns compliment each other... and if you are going to have EO and radar sensors on the platform anyway then adding missiles and guns makes sense.

Guns are cheap but are limited range and the different combinations have different limitations... big calibre have reduced PK performance without guided shells, while smaller rounds need to be fired in enormous volumes for effect to hit a moving target.

Missiles are relatively more expensive and are not so good at very short ranges, but are much better at longer ranges and have a much better shot to kill ratio so fewer missiles are needed.

57mm calibre guns actually offer anti swarm capabilities with guided shells, so in an attack you could fire 40km anti aircraft SAMs at say an F-35 while the 57mm cannon deals with any drones or ordinance the F-35 might launch... just as an example.

If we translate that to the georgian conflict small light UAVs had a tiny IR signature so most MANPADS were not suitable for bringing them down, while tradition air defence weapons of the VDV were inadequate as the ZU-23 lacked the altitude performance to engage small drones at 3-4km altitude and the SA-13 would not have gotten a reliable lock. An SA-8 might have done the job, but they only had BUK which is seriously over kill. They also used MiG-29s with R-73s... but a gun/missile platform able to choose between firing a guided 57mm shell or even launching a light missile like Pantsir-SM would have been a much more cost effective option.

eehnie wrote:

Rmf wrote:then produce more units.
anyway 2-57mm gunns ,and 12 missiles would be really  powerfull.

To produce more units is far more expensive.

well by nature this short range systems are mass produced and sensors are not too much big nore powerfull- thus not too expencive, and more units gives better battle damage resistance and cross coverage.

datalinks can share target data so the air defence unit with 57mm guns and SA-22 missiles could pass target data to an IFV unit operating closer to where the target is and they could open up with their 57mm guns where needed or Verba MANPADS if appropriate.

Even tanks can fire 125mm guided shells at aircraft when needed.... and have the autotrackers to follow moving targets...

Rmf wrote:

eehnie wrote:

Rmf wrote:then produce more units.
anyway 2-57mm gunns ,and 12 missiles would be really  powerfull.

To produce more units is far more expensive.

well by  nature this short range systems are mass produced and sensors are not too much big nore powerfull- thus not too expencive, and more units gives better battle damage resistance and cross coverage.

Yes, I agree, but it is not the same to produce 1000 57-4 vehicles, than 4000 57-1 vehicles. As example it means 4000 engines instead of 1000, it means 4000 drivers instead of 1000,... it is a cost chain. The countries that go to a 57-1 configuration surely will not order more than 100 of them.

Technologicaly a 57-4 configuration is not a solution difficult to reach. The control of fire is not a problem. It is significantly more difficult to reach good systems of projectile guidance. But still I do not see trouble to use guided ammunition in a 57-4 configuration in the amounts that the current guidance systems allow.

that vehicle to carry 4= 57 mm gunns will have to be much bigger and with bigger engines ,less mobile and youll have less coverage then solo systems...

Even the ZSU-57-2 needed a tank chassis to move around the battlefield and could only carry about 300 rounds of ammo in its huge open turret with no sensors except optical sensors for tracking and engaging targets.

To be brutally honest four x 57mm guns firing at once will be hard to stabilise and will greatly reduce accuracy.

An S-60 battery with 6 x 57mm guns on independent mounts could be tied into radar directors to give reasonable accuracy but still thousands of rounds were fired for not a huge number of kills in each engagement.

With guided shells then only a few shells would need to be fired so it would make more sense to reduce to one gun.

this would make the platform smaller and cheaper and simpler and allow rather more space for ammo and sensors.

In a direct fire mode most of the rounds can be unguided and would likely be very effective at battlefield ranges. Guided shells will only become more and more effective and cheaper... especially if the guidance and control package can be mass produced... a version for the 57mm shell could be adapted to be fitted to 80mm unguided rockets or other unguided weapons as a cheap mass produced system for aircraft and ground based systems.

Even 57mm gun armed BMPs could use simple guided rounds to hit specific targets out to extended ranges including aircraft.

GarryB wrote:Even the ZSU-57-2 needed a tank chassis to move around the battlefield and could only carry about 300 rounds of ammo in its huge open turret with no sensors except optical sensors for tracking and engaging targets.

To be brutally honest four x 57mm guns firing at once will be hard to stabilise and will greatly reduce accuracy.

An S-60 battery with 6 x 57mm guns on independent mounts could be tied into radar directors to give reasonable accuracy but still thousands of rounds were fired for not a huge number of kills in each engagement.

With guided shells then only a few shells would need to be fired so it would make more sense to reduce to one gun.

this would make the platform smaller and cheaper and simpler and allow rather more space for ammo and sensors.

In a direct fire mode most of the rounds can be unguided and would likely be very effective at battlefield ranges. Guided shells will only become more and more effective and cheaper... especially if the guidance and control package can be mass produced... a version for the 57mm shell could be adapted to be fitted to 80mm unguided rockets or other unguided weapons as a cheap mass produced system for aircraft and ground based systems.

Even 57mm gun armed BMPs could use simple guided rounds to hit specific targets out to extended ranges including aircraft.

I have not done the calculus, but at a first preview I do not have the impression that the 57-4 configuration would be too difficult to reach. The reasons for it are:

- The energies involved in the firing of 4 57mm projectiles at the same time are surely lower than the energies involved in the firing of 1 152mm projectile since the overall weight of the sum of the 4 projectiles is lower than the 152mm projectile. It means that a platform that resists the firing of 152mm ammunition should be likely enough for a 57-4 configuration. As example the weight of the 2S3 and the 2S5 of 152mm is of 27,5 tons. I can not assure it, but I would not rule out that the Kurganets and Bumerang platforms would be enough for a 57-4 configuration. I would try it.

In the other side, I do not think that the 57-1 configuration would be accepted in the Russian Armed Forces in something smaller or less armoured than a BMD-4M, because the criteria about safety of the crew would be applied.

Then, following with the example I tend to think that the most likely situation would be 1000 57-4 Kurganets/Bumerangs vs 4000 57-1 BMD-4M. I would expect the economic analisys to be favourable to the first option.

- Surely the system of stabilization of a 57-4 configuration would be done using subsystems for every barrel, that would not be too differents to the system of stabilization that would be used for a 57-1 configuration. Surely for a good stabilization would be required some aditional thing, but my impression is that it would be doable without affect to the rate of fire.

- The energies involved in the firing of 4 57mm projectiles at the same time are surely lower than the energies involved in the firing of 1 152mm projectile since the overall weight of the sum of the 4 projectiles is lower than the 152mm projectile. It means that a platform that resists the firing of 152mm ammunition should be likely enough for a 57-4 configuration. As example the weight of the 2S3 and the 2S5 of 152mm is of 27,5 tons. I can not assure it, but I would not rule out that the Kurganets and Bumerang platforms would be enough for a 57-4 configuration. I would try it.

In the other side, I do not think that the 57-1 configuration would be accepted in the Russian Armed Forces in something smaller or less armoured than a BMD-4M, because the criteria about safety of the crew would be applied.

You are contradicting yourself... first you say the recoil from four 57mm guns does not exceed a single 152mm gun, and so a vehicle with 4 x 57mm guns could be as light as a current vehicle with a 152mm gun, but then you say current levels of protection are not acceptable... which would apply to the 152mm gun armed vehicles you mentioned...

Then, following with the example I tend to think that the most likely situation would be 1000 57-4 Kurganets/Bumerangs vs 4000 57-1 BMD-4M. I would expect the economic analisys to be favourable to the first option.

You are looking at this the wrong way. four x 57mm gun barrels has the only advantage of firing four times as many rounds as a single gun armed vehicle... rate of fire is very important for unguided guns of small calibre like 23mm or 30mm cannon because the more projectiles you get into the air the better the saturation of the area where the target will be is denser making for a better hit probability.

The problem is that no 57mm gun... or even 35mm gun like the Gepard achieve their effectiveness by high rate of fire... they simply dont fire fast enough to get enough lead in the air... they have to rely on accuracy for effect and in the case of 57mm guns on guided shells.

23mm Shilka replaced the 57mm gun because the high rate of fire meant 200 shots could be fired at a piece of space in the sky where the target was flying towards. It wasn't super accurate so those 200 shells were scattered in a large cluster... which is a good thing because between the time the rounds are fired and the few seconds until they pass through the air their were aimed at the target could change speed or turn so the fact that they were all over the place just increased the chance of a hit. The higher density just made it less likely the target could fly through the shells and get through without a hit.

The 23mm Shilka was replaced by the Tunguska because the Tunguska had heavier 30mm cannons and a higher rate of fire with two twin barrel guns (5,000 rpm vs 4,000 rpm) and a longer range and heavier HE shell.

The 57mm gun will replace the 30mm calibre guns because it has better range and hitting power but its low rate of fire is compensated by the fact that the rounds will be guided to the target so far fewer rounds will be needed.

Having four barrels is not a help because it does not rely on rate of fire for effect... it relies on guided shells to be effective.

- Surely the system of stabilization of a 57-4 configuration would be done using subsystems for every barrel, that would not be too differents to the system of stabilization that would be used for a 57-1 configuration. Surely for a good stabilization would be required some aditional thing, but my impression is that it would be doable without affect to the rate of fire.

Stabilising four barrels would require a much better stabiliser and the internal space from four guns means less room for ammo and ammo handling systems... a big vehicle might carry 500 rounds, but with four guns it will use up ammo much faster and need to be resupplied more often.

I think a single barrel gun vehicle (note even the navy model of the 57mm gun system shows just one gun so if they don't bother with four I rather doubt the army will bother... even with one gun it will be an effective CIWS replacement being able to hit targets beyond the 4km effective range of the 30mm gatlings).

If it was 23mm then 30mm now 57mm, you can go directly for a 100mm antiaircraft gun without doing the 57mm. In tandem with the pantsir's 30 mm guns it will be more effective than 57mm.

GarryB wrote:

- The energies involved in the firing of 4 57mm projectiles at the same time are surely lower than the energies involved in the firing of 1 152mm projectile since the overall weight of the sum of the 4 projectiles is lower than the 152mm projectile. It means that a platform that resists the firing of 152mm ammunition should be likely enough for a 57-4 configuration. As example the weight of the 2S3 and the 2S5 of 152mm is of 27,5 tons. I can not assure it, but I would not rule out that the Kurganets and Bumerang platforms would be enough for a 57-4 configuration. I would try it.

In the other side, I do not think that the 57-1 configuration would be accepted in the Russian Armed Forces in something smaller or less armoured than a BMD-4M, because the criteria about safety of the crew would be applied.

You are contradicting yourself... first you say the recoil from four 57mm guns does not exceed a single 152mm gun, and so a vehicle with 4 x 57mm guns could be as light as a current vehicle with a 152mm gun, but then you say current levels of protection are not acceptable... which would apply to the 152mm gun armed vehicles you mentioned...

No this is not right. I said that I would try for the 57-4 configuration the current platforms in the weight class of the 2S3 and 2S5. Of course the Kurganets and Bumerang platforms meet the current requirements for safety of the crew, even better than the BMD-4M platform, and it surely being mechanically stronger than the platform used for the 2S3 and 2S5.

GarryB wrote:

Then, following with the example I tend to think that the most likely situation would be 1000 57-4 Kurganets/Bumerangs vs 4000 57-1 BMD-4M. I would expect the economic analisys to be favourable to the first option.

You are looking at this the wrong way. four x 57mm gun barrels has the only advantage of firing four times as many rounds as a single gun armed vehicle... rate of fire is very important for unguided guns of small calibre like 23mm or 30mm cannon because the more projectiles you get into the air the better the saturation of the area where the target will be is denser making for a better hit probability.

The problem is that no 57mm gun... or even 35mm gun like the Gepard achieve their effectiveness by high rate of fire... they simply dont fire fast enough to get enough lead in the air... they have to rely on accuracy for effect and in the case of 57mm guns on guided shells.

23mm Shilka replaced the 57mm gun because the high rate of fire meant 200 shots could be fired at a piece of space in the sky where the target was flying towards. It wasn't super accurate so those 200 shells were scattered in a large cluster... which is a good thing because between the time the rounds are fired and the few seconds until they pass through the air their were aimed at the target could change speed or turn so the fact that they were all over the place just increased the chance of a hit. The higher density just made it less likely the target could fly through the shells and get through without a hit.

The 23mm Shilka was replaced by the Tunguska because the Tunguska had heavier 30mm cannons and a higher rate of fire with two twin barrel guns (5,000 rpm vs 4,000 rpm) and a longer range and heavier HE shell.

The 57mm gun will replace the 30mm calibre guns because it has better range and hitting power but its low rate of fire is compensated by the fact that the rounds will be guided to the target so far fewer rounds will be needed.

Having four barrels is not a help because it does not rely on rate of fire for effect... it relies on guided shells to be effective.

- Surely the system of stabilization of a 57-4 configuration would be done using subsystems for every barrel, that would not be too differents to the system of stabilization that would be used for a 57-1 configuration. Surely for a good stabilization would be required some aditional thing, but my impression is that it would be doable without affect to the rate of fire.

Stabilising four barrels would require a much better stabiliser and the internal space from four guns means less room for ammo and ammo handling systems... a big vehicle might carry 500 rounds, but with four guns it will use up ammo much faster and need to be resupplied more often.

I think a single barrel gun vehicle (note even the navy model of the 57mm gun system shows just one gun so if they don't bother with four I rather doubt the army will bother... even with one gun it will be an effective CIWS replacement being able to hit targets beyond the 4km effective range of the 30mm gatlings).

We do not know the rate of fire of the new 57mm gun, but there is something clear: We can not be talking about the ZSU-57-2, a weapon which production finished in 1960 like if it would be the state of the art on rate of fire and stabilisation for this caliber.

The ZSU-23-4 replaced the ZSU-57-2 thanks to have better rate of fire, but more importantly still, because then the 23mm ammunition was able to make damage to the aircrafts at the time. If we talk about a successor of this weapon, it must have rate of fire to create enough density of fire and also must have enough caliber to make damage to the aircrafts. For it, the new 57mm gun would not need to reach the same rate of fire of the ZSU-23-4 in a 57-4 configuration, but would need to surpass clearly to the ZSU-57-2. And this is fairly possible, because the ZSU-57-2 technologically is a weapon of the 1950s.

If it was 23mm then 30mm now 57mm, you can go directly for a 100mm antiaircraft gun without doing the 57mm. In tandem with the pantsir's 30 mm guns it will be more effective than 57mm.

If we look at WWII tank based anti armour guns... at the start they were 37mm, 45mm and 50mm and even 57mm calibre guns but then they went from a dedicated high velocity smaller calibre gun to a multi purpose larger calibre with a good HE round as well in the 76.2mm guns.

They could have jumped straight to 152mm guns but the weight and recoil and other issues with such a calibre like lack of ammo storage space meant going to 76.2mm or 85mm or 90mm made more sense at the time.


They could go for a 125mm gun that can kill enemy MBTs but a smaller lighter gun makes more sense for now.

No this is not right. I said that I would try for the 57-4 configuration the current platforms in the weight class of the 2S3 and 2S5. Of course the Kurganets and Bumerang platforms meet the current requirements for safety of the crew, even better than the BMD-4M platform, and it surely being mechanically stronger than the platform used for the 2S3 and 2S5.

I don't think there will be a 152mm calibre Kurganets or Boomerang. We have seen a 152n gun armed Coalition based on the armata chassis and I suspect the 152mm gun armed vehicle for the lighter vehicle units will be truck based but using an engine from the lighter vehicle units... Kurganets and Boomerang are similar weights and likely share an engine family that will also be used in the truck based 152mm artillery gun used to support that unit.

We do not know the rate of fire of the new 57mm gun, but there is something clear: We can not be talking about the ZSU-57-2, a weapon which production finished in 1960 like if it would be the state of the art on rate of fire and stabilisation for this caliber.

No we don't know the rate of fire of the new gun, but we do know it will likely have an automated ammo feed system as opposed to large heavy four round clips as used on the ZSU-57-2 and S-60 AAG.

Rate of fire will likely be in the 120-200 rpm range I suspect, which is plenty for guided shells and totally inadequate for even a 4 barrel battery.

The ZSU-23-4 replaced the ZSU-57-2 thanks to have better rate of fire, but more importantly still, because then the 23mm ammunition was able to make damage to the aircrafts at the time.

The ZSU-57-2 replaced the 37mm calibre AAG from WWII and improved its performance with longer range and more powerful ammo that was rather devastating if you could get a hit.

The problem was that with very fast targets getting that hit was rather unlikely without radar guidance and fast turning turrets and launching a lot of rounds very rapidly in the direction of the target... the 23mm weapons were vastly superior in that they could put up a wall of shells rapidly in a short burst at a small fast moving target. The 30mm replaced the 23mm because it could fire at a higher rate with heavier more powerful rounds that reached to a greater effective range.

Without guided shells the 57mm would not be replacing the 30mm in air defence roles.

In the anti IFV role the 57mm is replacing the 30mm cannon shell because the latter has become much less effective in penetrating enemy armour.

It is the unique combination of armour penetration performance in the anti IFV role and with guided shells the ability to hit airborne targets effectively with a few shots that makes it also effective in the anti aircraft role too that makes the 57mm round a useful new round.

For anti armour use and anti aircraft use however high rate of fire is not desirable or particularly useful.

It would only be useful in using unguided rounds against air targets... and for that role even 20 barrels would not put up enough ammo to make it viable as an anti aircraft gun with unguided shells. With guided shells just one barrel makes the most sense in terms of cost and complexity and onboard ready to fire ammo etc etc.

If we talk about a successor of this weapon, it must have rate of fire to create enough density of fire and also must have enough caliber to make damage to the aircrafts. For it, the new 57mm gun would not need to reach the same rate of fire of the ZSU-23-4 in a 57-4 configuration, but would need to surpass clearly to the ZSU-57-2. And this is fairly possible, because the ZSU-57-2 technologically is a weapon of the 1950s.

With guided shells a much lower rate of fire of even the ZSU-57-2 would be more than effective. Just having one gun means traverse and elevation can be made faster and more accurate and recoil during firing will be rather less too and the internal ammo delivery mechanism will be able to hold more ammo for the one gun, instead of the complexity of trying to feed four separate guns.

This is what I was commenting. Opening the range for rate of fire with 120 rounds per minute by barrel, for a 57mm weapon of today, you seems to consider the ZSU-57-2 like the state of the art, because this rate of fire was reached by the ZSU-57-2 60 years ago (240 for the two barrels combined), and this gun is technologically of the 1950s with all that it means.

I expect different numbers, if this is true the improvement since the 1950s would be fairly weak and this weapon would not succeed for any role.

It is necessary to take into account that the current 2A38 30mm used by the SA-22 Pantsir fires at 1950-2500 rounds per minute rate of fire (3900-5000 for the two combined).

Also I expect a 152mm gun for the Kurganets platform, not to reach the range of the 2S35, but yes in the mold of the 120mm gun that combines direct and indirect fire. But this is a different history.

https://www.youtube.com/watch?v=XKVIXXabkl0

I expect different numbers, if this is true the improvement since the 1950s would be fairly weak and this weapon would not succeed for any role.

Firing a million rounds a minute would not be an improvement for this weapon... having a higher rate of fire with no accuracy improvement just means wasting more ammo and the ammo for the 57mm gun is huge so there is a limit to how much a vehicle can carry.

The improvement that is critical is guided shells...

The old ZSU-57-2 carried about 300 rounds in four round clips that had to be manually loaded. the roof of the vehicle was open topped because it had a large crew that included two loaders loading four round clips into the guns to keep them fed.

A 300 round ammo capacity meant against an aircraft target it would need to fire for a long period to assure a kill... with 300 rounds the odds are that a full ammo load might lead to 3-4 kills with a good crew and a not very fast target.

With guided shells then you would expect up to 100 kills as a certainty... and more importantly those kills could be over much greater ranges and a much wider range of targets including very small ones the old system could never hope to get.

So the advantages over the old system is the ability to hit small fast manouvering targets at longer ranges... much faster and using much less ammo... maybe 2-3 rounds per kill.

If you only use 2-3 rounds per kill then it makes no sense to use a four barrel arrangement... a single barrel weapon is perfectly fine.

[qutoe]It is necessary to take into account that the current 2A38 30mm used by the SA-22 Pantsir fires at 1950-2500 rounds per minute rate of fire (3900-5000 for the two combined). [/quote]

They do because they have to. For a target at 4km or near max effective range for the 30mm round the shell flight time can be 10 seconds or more... in 10 seconds you can project a predicted point where the target will be when the shells arrive, but after the rounds are fired and until they arrive the target could slow down or speed up or turn, which makes the aim point a box rather than a single aim point. The spread of shells means that if the target is not in the precise place it was expected to be there is still a chance of a hit.

The more rounds you fire the denser the pattern of hits so the smaller the target can be and still be hit. With 30mm shells a 200 round burst has a good chance of hitting a large object at 3km range, but a poor chance of hitting a much smaller target like a cruise missile.

New ammo with timer fuses that make the shells explode without having to contact a target mean even better performance because shells exploding spread a pattern of shrapnel around the interception area greatly increasing the chance of a hit... each of the 200 shells scatter tens of thousands of fragments in the area the target will be.

Obviously the ideal is to be able to correct the first round fireds trajectory so no matter what the target does the first round will still hit... that is the logic behind the 57mm rounds... so rate of fire is no longer important... shell weight means range is greatly increased too.