2S38 Derivatsiya-PVO 57-mm SPAAG

How will these 57mm naval gun intercept sea skimming cruise missiles? Those missiles are capable of maneuvering. Probably capable of terminal maneuvering as well.

The same way a 30mm twin gatling gun mount does... the target is tracked and an interception point is plotted that includes the flight time of the shells (30mm or 57mm) and so you then fire a burst... in the case of 30mm cannon shells you might fire a 1-2 second burst for a manouvering target to send 200-400 cannon shells to intercept the target... those 200-400 shells wont hit one tiny point in space, they will be scattered all over the area around the aim point... now between the time the shells are fired and the time they reach the intercept point the missile might have sped up or slowed down or climbed or descended or turned or any combination of these things.. but a huge scatter of 400 30mm shells all over that area means even if it made all those course corrections... it is still effectively heading towards the boat and will probably be hit by more than one shell.

The difference a 57mm gun makes is that instead of firing 400 shells you fire 4 shells that bracket the interception point with air burst shells that spread thousands of high speed fragments to fill that intercept box... the point is that the 30mm guns can start firing at about 4km where they could be effective with perhaps point blank being about 2.5kms where targets are not getting past without some hits.... with a 57mm gun they can start firing at about 12km and each time the missile gets past another burst can be fired to intercept it closer in.

Of course a target that is manouvering hard will have a TOR or Pantsir missile fired at it, or a guided 57mm shell to ensure a kill, but most missiles just rely on flying low and fast and straight... in fact an option for the 57mm gun would be to hit the sea water in front of the missile... smacking in to a wall of sea water at high subsonic flight speed will ruin any missiles day... subsonic would be destroyed... faster would be obliterated...

A computer predicts their course with the help of radars/optics and the gun fires a few shots onto that heading. Then you hope that the missile won´t change its flightpath in the last second

Ideally you don't want the missile getting too close... a 250kg warhead going off 300m away can do some damage, but most gun systems become more effective the closer the target... but any incoming missile pulling hard manouvers will be engaged with a missile... a Harpoon flying in level and straight is ideal cannon fodder however.

Plus guns are fully dual purpose and can be used for warning shots... an air burst 57mm shell above a speed boat would be devastating... 30mm pretty effective too...
New airburst 30mm shells makes them more useful too.

The very large Soviet models were designed to penetrate very strong IADS, and sometimes they carried jammers and armour and decoys and other goodies just to increase their chances of getting through... but the measure counter measure game is tricky... if you know the incoming missile has a jammer then a jamming signal is something you could launch a missile at to home in on the jamming signal... for it to detect it is being attacked by an anti jamming missile it would need to detect the incoming missile and also detect that it has a passive homing seeker... which is near impossible to fit on a missile... especially the tiny western anti ship missiles.

The US has not expected to be attacking a real carrier group with a solid IADS, but these days even Russian corvettes have the equivalent of a couple of S-350 batteries and a few Panstir and TOR batteries in support and even their artillery (large calibre guns) can shoot down aerial targets these days too... so the Americans are having a bit of a crisis of issues because even China is developing new ships with capable air defence systems and IADS... when your enemy is launching hundreds or thousands of slow low flying cruise missiles then the solution is an IADS... that is what they are for... to prevent air defence units from being overwhelmed by using them at peak efficiency... select the biggest threat and deal with that first while all air defence assets are dealing with what they can deal with... it is no guarantee of survival but offers the best protection solution.

Russia, like any country, will simply have to rely on intel to determine what threats are out there and how they can be defeated... sometimes they will surprise... for the west their intel services are inept... they were told for years about rocket powered torpedoes and land attack cruise missiles and the effectiveness of supersonic anti ship missiles and that they were working on hypersonic models... they pretty much totally ignored them and gave all sorts of excuses... they wont be reliable... they wont be accurate... they wont be able to find the targets because their C4IR is rubbish etc etc.... they constantly under estimate their enemies and over estimate their own potential.

That nuclear powered unlimited range cruise missile was shown on video simulation flying over sea but flying around radars... so it likely has equipment on board that can detect radar emissions of ships looking for targets to shoot down so it would adjust its flight path to skirt around such things to avoid interception... of course with a normal cruise missile you would want it to fly at medium altitude to improve range performance because conventional turbojet engines work best at higher altitude, but with nuclear propulsion it could fly low all the way making it a much more difficult target...

Which missiles? Are they still in use?

The big anti carrier models... Granit, Vulcan, etc etc

So it's basically a cross between a cruise missile and a loitering munition like Harop, isn't it?

Not really... it is not really gathering intel... it doesn't pass the locations of air defence networks on to anyone... it just uses that information to skirt around air defence sites on land and at sea... to make it more likely to make it to its target...

Interesting comparison of the two different vehicles though.

The on topic air defence gun with the muzzle brake and the two vehicles with the new 57mm grenade launcher that doesn't have a muzzle brake fitted...

Raises the interesting question... the T-15 was the BMP version of Armata but with a 30mm cannon turret, but this vehicle with the 57mm grenade launcher should also be the BMP version... and so would the version with the high velocity 57mm gun too...

There are two different guns... both are 57mm calibre.

One is a gun and the other is a grenade launcher... normally it would not be a big deal... the upgraded BMP-2s have a 30mm cannon and a 30mm grenade launcher too.

The problem is that you can normally distinguish the two weapons as a cannon with high velocity rounds and a grenade launcher with heavier projectiles and low velocity shells.

In this case however the grenade launcher can actually fire APFSDS rounds which are high velocity armour piercing rounds so you can't call it a low velocity grenade launcher... even though the HE shell is enormous compared with the propellent case just like with the 30mm grenade launcher round.

It is like the difference between the 100mm rifled gun of the BMP-3 and the 100mm rifled gun of the T-55... same calibre, but different shell case size...

The rifle calibre machine gun mount being external is interesting... if they develop some air burst 40mm grenades they could mount a 40mm grenade launcher there instead to hit enemy drones at closer ranges... if they can do it for 30mm cannon shells then it should be possible with a 40mm grenade....

The MG is there to fight infantry. No way they skip it.

A 40mm grenade launcher could kill troops out to 2.5km rather more effectively and efficiently than a rifle calibre machine gun...

@magnumcromagnon

Amazing photo...

Interesting that it has not muzzle brake but it does have the barrel water cooling system tube...

Duh... stupid me...

A muzzle brake makes sense for a single barrel AA gun... it reduces recoil so the barrel moves of the point of aim less with each shot, and of course it creates a place to put induction coils for smart fuse ammo and for determining muzzle velocity of rounds as they are fired in real time... which can be programmed in to the ballistics computer to make bursts of shots more accurate... and of course to set time fuses as the rounds are fired...

Just as a test I am going to like the original photo post again and dislike this post twice to see if either is possible.