2S35 Koalitsiya-SV 152mm

Why would they waste time and money (more than usual that is) on pair of guns which have never been used on a couple of ships which will be in service for couple of decades more?

Because they already spent money developing the guns in a joint venture with the Army, and when the new build Destroyers are ready they will likely be fitted with these guns as will the new cruisers they design to operate with their carriers when the upgraded Kirovs and Slavas are retired.

It is a chance to get the gun on a ship and tested and fully operational so that when the new destroyers are ready to be built they will have all the bugs and kinks ironed out and also have a powerful gun system at sea ready to use much earlier than if they leave it till their first brand new destroyer hits the water.

Having naval guns able to use this ammo means larger production volumes so it will be cheaper for both branches and offer capabilities than the current 130mm guns on their frigates can't match. In comparison the 130mm guns reach about 25km with a 34kg projectile... even just current 43kg 152mm shells reach 70km or so with GLONASS guidance.

Navy R&D money developing new anti aircraft and other shells will make the Army ammo cheaper and vice versa...

Hell with a 170km range with a reduced HE payload they could use the damn thing to direct depth charge attacks on submarines 150km away from the ship and land 90-120 charges a minute if they want to...

Lord knows they have screwed up enough on overhaul of first​ one and they are supposed to fiddle some more with something that is glorified ballast at this point in time?

Yeah, using upgrades of existing types to test new stuff is silly... much smaller to make brand new types where everything is brand new and untested so when something goes wrong you don't know what the real cause is so you have 1,000 different problems with the design all at once and you don't know if it is the system itself at fault or a component in another system it should be interacting with... so you just blame something else that is not working for your part to not work at the moment... ie Ford class CVN, Zumwalt Destroyer class, LCS frigate wannabe...

Upgrades of the Kirovs and Slavas are going to be tricky because it has not been done before so there is no rule book, but it is a good chance to test new technology that is going to go on their new build replacements... otherwise they could keep using the Granits instead of the UKSK launchers and save some money...

GarryB wrote:...when the new build Destroyers are ready...

There will be no new buld destroyers, even new build frigates are delayed and standard frigates they build now are made in boutique numbers

Even guns on few frigates they build now are double the useful size and are just taking up space which could have been used for more missiles

Nobody needs guns on ships in this day and age other than for warning shots, 52mm is more than enough for that

More missiles have been launched by measly Russian fleet in Syrian War than all the shells that have been fired by all ships in all navies of the world since the WW2

PapaDragon wrote:

GarryB wrote:...when the new build Destroyers are ready...

There will be no new buld destroyers, even new build frigates are delayed and standard frigates they build now are made in boutique numbers

Even guns on few frigates they build now are double the useful size and are just taking up space which could have been used for more missiles

Nobody needs guns on ships in this day and age other than for warning shots, 52mm is more than enough for that

More missiles have been launched by measly Russian fleet in Syrian War than all the shells that have been fired by all ships in all navies of the world since the WW2

That's a load of bosch

First of all guns are viable for engaging fast torpedo boats, small landing craft, commando rafts, supply vessels and anything else you spot that is not armed with missiles and that you don't want to waste a missile on.

Second of all shore-bombardment; always a nice bonus for ships in support of amphibious operations

Third of all anti-air; with the continued development of fuses and directional warheads large-calibre naval guns have long been viable for engaging incoming missiles and the like.

Fourth, GarryB has a nice idea with possible depth-charge payloads. In the future we can see guns being used for anti-submarine duty rather than missile-torpedos and helicopters.

Guns are cheap to buy and cheap to use as long as they are not made for the US Navy.

More missiles have been launched by measly Russian fleet in Syrian War than all the shells that have been fired by all ships in all navies of the world since the WW2

And if the Syrian terrorists mounted a small boat raid to try to do something about those Russian ships it will be the high rate of fire 76mm and 100mm and 130mm guns as well as those 30mm gatlings that would rip them a new one at a fraction of the cost of one missile.

The Soviet Navy reintroduced the Sverdlov Cruiser because it wanted to use its 152mm guns for shore bombardment to support troops landing from Ivan Rogov ships... they are building new helicopter landing craft... having 152mm guns on a ship to support operations would be very valuable.

During WWII such guns pummelled targets, but communication and command and control were not strengths down to that level.

With modern net centric forces like those equipped with Ratnik and the communications systems in their armoured vehicles and drones and attack helicopters a landing force able to call in precise shots with GLONASS guided 152mm artillery shells would make them enormously more capable... available 24/7 in any weather... what is not to like.

You could even use a drone with a laser target marker to mark floating mines for destruction with 152mm or even 130mm or 100mm rounds.

The Army and Navy have already paid the development costs of this weapon, and by actually using it they benefit from that money already spent, and can invest new money in rounds both can further benefit from... like a jammer shell that can be fired away from friendly forces to attract enemy missiles with home on jam performance... as I mentioned depth charge shells... the Soviets developed guided depth charges that basically glide down in a circular search pattern looking for submarines with a small sonar as used on passive sonar buoys that is quite cheap... a 152mm version with steering fins and a sonar shouldn't be totally impossible... if the enemy sub is deep then a simple shaped charge to punch a hole in it will do some serious damage... let alone getting attacked by 10 of them... one hit might not sink a sub but will impact its performance and the depths it can operate and make it very vulnerable to further attacks...

A 203mm version would be interesting because the actual guided depth charge (S3V) is 211mm in diameter and weighs 94kgs, so while it is slightly wider than a 203mm shell it is actually about 15kgs lighter.

Even if it only had a range of 50km it would be a useful addition to a cruisers armament...

They have a range of anti sub/anti diver/anti torpedo rockets fired from the various RBU launchers... some of which could potentially be supported or supplemented by 100mm or 130mm versions as well as 152mm and 203mm... using the gun turrets means it would be more stealthy than an RBU system...

In fact just flares and Chaff dispensers could be supported by flare and chaff shells from the large calibre guns to set up defences rapidly and to keep them working for longer periods...

flamming_python wrote:First of all guns are viable for engaging fast torpedo boats, small landing craft, commando rafts, supply vessels and anything else you spot that is not armed with missiles and that you don't want to waste a missile on.

And simple 57mm is more than enough to handle all of it

One round from Coast Guard CIWS was enough to stop the Ukrainians dead last year

Even 57mm looks like overkill with this in mind

GarryB wrote:...as well as those 30mm gatlings that would rip them a new one at a fraction of the cost of one missile

Thank you for helping prove my point

flamming_python wrote:Second of all shore-bombardment; always a nice bonus for ships in support of amphibious operations

When was the last time Russia did shore bombardment?

Last shore bombardment ever was in Gulf War and only reason it happened was because Pentagon told crews of Iowas to get rid of surplus shells before decommissioning

flamming_python wrote:Third of all anti-air; with the continued development of fuses and directional warheads large-calibre naval guns have long been viable for engaging incoming missiles and the like.

Do any of these guns have this feature or is it another thing that is made of ideas?

flamming_python wrote:Fourth, GarryB has a nice idea with possible depth-charge payloads.

Does this depth charge exists anywhere outside his idea? Somewhere in general vicinity of the real world?

And simple 57mm is more than enough to handle all of it

One round from Coast Guard CIWS was enough to stop the Ukrainians dead last year

Even 57mm looks like overkill with this in mind

You can make all the claims you like... if 57mm guns were so useful why are they so rarely fitted to older Soviet ships... the Ropochka landing ships had some and a couple of corvettes that were too light to fit 76mm guns is about it.

In comparison their new production vessels their corvettes have 100mm guns and their Frigates have 130mm guns... previously their corvettes had 30mm only or 57mm or at best 76mm guns, while their standard frigate design... the Krivak generally had 76mm guns. Their destroyers were mixed with their Udaloys with 100mm gun turrets and the Sovremmeny class destroyers with 130mm guns and of course their cruisers some started out with 100mm gun mounts but they ended up fitting them with 130mm guns... sometimes in fewer turret mounts.

The US in comparison brought some old dinosaurs back from the dead in the Iowa class ships for naval gun support operations... I would think a 152mm gun mount would be much cheaper and in fact with better range an accuracy though with rather less penetration and explosive content.

Thank you for helping prove my point

That guns are more flexible and useful than missiles... no problem...

Bigger guns offer even more flexibility, though of course you have to be careful not to make the stupid mistake the Americans made where the requirements for range were absurd so they ended up creating a gun launched multi stage missile that cost as much as a missile... the point of making it a gun based round is to reduce costs by reusing the propellent component in a gun, rather than using a missile given a push start by a gun...

Result was a missile range missile with the costs of a missile instead of a missile range gun with the costs of a gun.

When was the last time Russia did shore bombardment?

They could have used it in Georgia... if their landing parties had met resistance...

But they need shore bombardment capacity if they are building helicopter landing ships and are continuing to fund Naval Infantry forces.

Last shore bombardment ever was in Gulf War and only reason it happened was because Pentagon told crews of Iowas to get rid of surplus shells before decommissioning

When was the last time anyone used a strategic nuclear ballistic missile?

They have not. But the point is that there are scenarios where they could use it, and other uses as well... simply getting a ship to stop that is more than 5km away and missile might sink it, but an airburst 152mm shell 200m in front of her bow says stop.... and if they don't listen a 152mm shell into her bridge or rear rudder section will make her stop... you can't really be that selective with most missile options...

Right now America is trying to solve its inadequacies regarding military power through concepts centering around swarm drone technology... nothing deals with large numbers of enemy platforms than airburst heavy calibre artillery... on land... in the air... or on water.... and a naval gun should really have outstanding firing rates too because of the fully automated ammo handling systems.

Such airburst rounds that can be set off amongst a group of drones is as much use to the army as the navy...

The coastal gun system Bereg could be upgraded to 152mm calibre too... which will extend their range and lethal potential and accuracy... and there are supposed to be quite a few of those around the place.

Do any of these guns have this feature or is it another thing that is made of ideas?

Of course they do... the 130mm A3-UZS-44R is an airburst round intended for use against aircraft of all types and also anti ship missiles as well as soft shore and sea targets like light structure boats and troops in the open... it uses a proximity fuse and airbursts near the target... the 100mm round is called A3-UZS-58R round that uses the same AR-32 radio fuse. They have other rounds with timed mechanical fuses but the proximity fuses are more effective.

The 76mm gun uses the A3-UZSB-62RP round with the AR-51L radio fuse.

I would suspect that with the 30mm shells getting laser initiated fuses for air burst that new 57mm rounds already have that capacity too.

Does this depth charge exists anywhere outside his idea? Somewhere in general vicinity of the real world?

You are right... just because it could work and might be useful without being expensive... it must be a bad idea.... because everything that us currently done is right so anything new must be wrong.

BTW 57mm good enough on its own?

Perhaps after it has been improved and upgraded via Army programmes to expand and improve the ammo options...

Imagine what they could do with the other calibres in service... with such changes...

GarryB wrote:They could have used it in Georgia... if their landing parties had met resistance...

If your landing parties are facing resistance that make you desperate enough to have to bring your ships in artillery range of such miniscule enemy's land army it means that your airforce and army dropped the ball big time

But you know what Russian Navy did use in Georgian War? Missiles

They used missiles to destroy Georgian Navy which was first actual use of Russian Navy since the WW2

Naval guns are great for fighting yesterday's wars but as Georgia and Syria demonstrated yesterday's wars are not today's wars and especially not tomorrow's wars

Every single cubic meter of space wasted on useless oversized guns is a space that will not be available for missiles which are actually useful armament as modern history has demonstrated

PapaDragon wrote:

GarryB wrote:They could have used it in Georgia... if their landing parties had met resistance...

If your landing parties are facing resistance that make you desperate enough to have to bring your ships in artillery range of such miniscule enemy's land army it means that your airforce and army dropped the ball big time

But you know what Russian Navy did use in Georgian War? Missiles

They used missiles to destroy Georgian Navy which was first actual use of Russian Navy since the WW2

Naval guns are great for fighting yesterday's wars but as Georgia and Syria demonstrated yesterday's wars are not today's wars and especially not tomorrow's wars

Every single cubic meter of space wasted on useless oversized guns is a space that will not be available for missiles which are actually useful armament as modern history has demonstrated

And which missiles should take their place exactly? the missiles they need more of use the UKSK launcher which last time I checked was too big to fit into the bow of any of the new frigates let alone a corvette.

Regarding missile numbers though there is a lot of wasted space aboard even Russian ships, perhaps they just are not comfortable with sending out frigates that carry a missile armament more expensive than a large destroyer.

The current gorshkov can carry up to 16 full size ASHMs and the newer ones will be able to carry 21 while the pindos frigates will only carry 8 small subsonic short ranged notions of anti ship capability.

If you are going to pay for over 100 zircons you may aswell pay for a nuclear powered heavy missile cruiser with a full layered air defence system so that you can keep you precious missiles afloat when you actually need them.


As for guns they are needed for various tasks related to defending your ships during peacetime and do contribute to CIWS capabilities, actually as far as I am aware poximity fused shells for naval guns have been in service since the 1960s.

Wheeled Koalitsiya also, interesting

Russia’s latest Koalitsiya wheeled howitzer enters trials

The version based on the Kamaz wheeled chassis has certain advantages, according to the developer

MOSCOW, May 26. /TASS/. The Burevestnik Central Research Institute (part of Uralvagonzavod defense manufacturer within the state hi-tech corporation Rostec) has started the trials of the latest wheeled version of the Koalitsiya-SV self-propelled artillery system based on the Kamaz-6550 truck chassis, the Uralvagonzavod press office told TASS on Tuesday.

The Burevestnik Central Research Institute has decided to expand the range of the artillery system’s modifications: with all the positive qualities of the tracked howitzer, its version based on the Kamaz wheeled chassis has certain advantages, the Uralvagonzavod press office quoted Burevestnik Chief Designer of the project and Department Head Vasily Nabatov as saying.

"First of all, wheeled vehicles can be used on general-purpose roads. They feature high mobility and large cruising endurance and have very high potential compared to tracked versions," Nabatov said.

As a result, the wheeled howitzer has turned out to be lighter, more mobile and easier to be transported by aircraft, which expands the range of its missions and the promptness of their fulfillment. The artillery gun’s service life has also been extended, the project’s chief designer said.

"By way of comparison: a tracked vehicle has a service life of about 5,000 km of run before major repairs. For a wheeled vehicle, 5,000 km is actually the completion of its run-in test," he said.

https://tass.com/defense/1160489

George1 wrote:Wheeled Koalitsiya also, interesting   ...

And the images, praise the Lord !!!






Those light brigades are about to get some heavy sticks

Self-propelled artillery 2S35-1 "Coalition-SV-KSh" mount on a wheeled chassis

The Coalition-SV on a wheeled chassis is a Russian 152-mm self-propelled artillery mount based on the KamAZ-6550 car. Tests are held at a special training ground in the Nizhny Novgorod region. Installation mechanisms are checked by specialists year-round during sea and fire tests. Self-propelled guns "Coalition-SV" can fire in series. This machine currently has no analogues in the world.

This self-propelled gun was developed at the Nizhny Novgorod Central Research Institute Burevestnik, a member of the Uralvagonzavod concern.

For the first time, self-propelled guns on a caterpillar base were demonstrated on May 9, 2015 in Moscow at the parade in honor of the 70th anniversary of Victory in the Great Patriotic War.

“We simply expanded the product line. It should be understood that caterpillar carriers, with all their positive qualities, namely, high carrying capacity, high cross-country ability, high degree of reservation, have a number of disadvantages. At the same time, a wheeled vehicle has several advantages: wheeled vehicles can be used on general roads, have greater mobility, have a longer power reserve, have a very high resource compared to tracked vehicles, ”said the chief designer of the department, the head of department of JSC“ Central Research Institute "Burevestnik" ”(part of JSC“ Concern Uralvagonzavod ”” of Rostec state corporation) Vasily Nabatov.

For comparison: tracked vehicles have a resource of the order of 5,000 km to overhaul, and for a wheeled vehicle, five thousand is, in fact, when the carrier’s run-in only ends. Cars are easier, more mobile, easier to transport by air, can travel longer distances more easily. Accordingly, the list and efficiency of the tasks is expanding, said Nabatov.

At the moment, 152 mm self-propelled guns on a wheeled chassis are made in a small series. This year, according to experts, it is expected to complete the tests. After that, a decision will be made on its manufacture for the army.



https://bmpd.livejournal.com/4038666.html

One of the samples from the pilot batch of new 152 mm 2C35 Coalition-SV self-propelled howitzers transferred to to the Central Military District



A press release from the Central Military District press service reports:

Eight units of the “Coalition-SV” interspecific artillery complex were first brought into the arsenals of the Central Military District for further shipment to the troops. The Coalition-SV is equipped with a modern 2A88 gun of a caliber of 152 mm with a firing speed of more than 10 rounds per minute, as well as a modern automation system for gun guidance, target selection and navigation.

The 152-mm self-propelled howitzer "Coalition-SV" is based on the platform of the T-90 tank and is designed to destroy the entire range of ground targets: command posts, communication centers, artillery and mortar batteries, armored vehicles, air defense and missile defense systems, as well as enemy manpower at a distance of up to 70 km.

The workplace of the gunner and commander of the Coalition-SV self-propelled artillery system is equipped with digital displays and integrated into a single automated tactical link control system that allows receiving target designations via a digital communication channel, providing round-the-clock monitoring of the terrain, autonomous calculation of shooting installations and adjusting fire in any weather conditions. The structure of the howitzer’s armament also includes a 6S21 remotely controlled turret with a Kord machine gun of 12.7 mm caliber.

https://bmpd.livejournal.com/4039042.html

Tiny alteration but I do like how barrel is now in horizontal position

Also, can anyone figure out weight of wheeled Koalitsia?

Looks light enough to fit on a cargo plane so VDV could definitely be interested in those

PapaDragon wrote:
Tiny alteration but I do like how barrel is now in horizontal position

Also, can anyone figure out weight of wheeled Koalitsia?

Looks light enough to fit on a cargo plane so VDV could definitely be interested in those

That's how it's always looked without the primary travel lock.

If your landing parties are facing resistance that make you desperate enough to have to bring your ships in artillery range of such miniscule enemy's land army it means that your airforce and army dropped the ball big time

AFAIK the landing was a Navy only affair... why would they want to get the Air Force or their Army involved if they didn't need to?

Having a cruiser sitting 60km off shore landing laser guided shells on target as needed is much simpler and cheaper than getting the Air Force involved...

But you know what Russian Navy did use in Georgian War? Missiles

Yes... they were spending money like they were American... for support of forces on land however missiles would have been less effective than good artillery support.

They used missiles to destroy Georgian Navy which was first actual use of Russian Navy since the WW2

The Russian Navy stopped existing at the end of WWI...

Naval guns are great for fighting yesterday's wars but as Georgia and Syria demonstrated yesterday's wars are not today's wars and especially not tomorrow's wars

Actually as electrical technology and EM technology improves guns are going to become much more relevant. The problem with the Zumwalts gun is not that it is a gun, but that it is trying to reach to ranges that only missiles can currently reach and a gun that fires missiles is not a gun... certainly not a good gun... they should have asked their own Army about the Sheridan and M60A2 tank. If they were a bit more sensible in their demands for range it could have been useful and over time improved to reach the goals they wanted. Instead, to reach the goals now they broke the whole idea behind the concept of cheap gun fire power...

Every single cubic meter of space wasted on useless oversized guns is a space that will not be available for missiles which are actually useful armament as modern history has demonstrated

So why are you even on this thread if guns are all useless Mr Kruschev?

Those light brigades are about to get some heavy sticks

Now I realise the 2S43 will be lighter and cheaper than this vehicle, but I would have to say that this vehicle offers probably 90% of the reduced operational costs of a wheeled version ( more expensive because of the turret, but that is only to buy and would not add to ongoing costs), and is probably a few tons heavier, but being able to shoot from position 360 degrees and full protection for the crew and likely excellent automated rate of fire rather than very slow manual loading...

I would think the combination of highly mobile but expensive tracked Coalition, wheeled and cheaper this wheeled version, and a towed gun you could drop by helicopter anywhere together with a light tractor vehicle like a BMD-2 or something to move it around, and that would be all they need for 152mm guns in terms of new weapons. The old weapons in that calibre are still useful, but these three options makes the other things like that 2S43 a bit redundant don't they?

At the moment, 152 mm self-propelled guns on a wheeled chassis are made in a small series. This year, according to experts, it is expected to complete the tests. After that, a decision will be made on its manufacture for the army.

Maybe this could compete with the 2S43 for the wheeled 152mm gun artillery category?

The extra cost for automated loading and reloading and 360 degree firing without needing to move the vehicle...

State tests of ammunition for the howitzer "Coalition-SV" will be completed in 2021

MOSCOW, May 27 - RIA News. State tests of full-time ammunition for the latest Russian self-propelled howitzer "Coalition-SV" will end in 2021, said in an interview with RIA Novosti the executive director of the project developer of these shells - the Techmash research and production corporation (part of the control circuit of the holding " Technodynamics " state corporation Rostec ") Alexander Kochkin.

“The specialists of our enterprise - the Bakhirev NIMI - began testing ammunition for the latest Coalition-SV self-propelled artillery mount - developed by the Central Research Institute Burevestnik produced by OA Uraltransmash (part of the Uralvagonzavod concern ). In this half-year we should get according to them, the letter “O”, the completion of state tests is most likely 2021-2022, ”Kochkin told the agency, speaking about the concern’s current projects.

https://ria.ru/20200527/1572044841.html

Does someone knows in this context what " letter 'o' means

Only see it fire forward and to the rear... will be interesting to see it fire to one side or the other...


Regarding the O... a Russian speaker could help perhaps with access to the original text?

GarryB wrote:Only see it fire forward and to the rear... will be interesting to see it fire to one side or the other...


Regarding the O... a Russian speaker could help perhaps with access to the original text?

THAT'S is the hard part, a tracked one have a lower sitting centre of gravity and tracks absorb well lateral movement, while a wheeled one risk to flip over.

Tactically however it is not so important to have a 360° for a long range artillery piece using scoop and scoot tactics firing some hundreds of meters farter or nearer from an objective is perfetly feasible, being able to fire +/- 60° both forward an into rear would be more than enough in all tactical situations.

Look at the video. Thanks to the lowered supports the truck don´t move an inch at the gun fires. Also I think the russian army/developers wouldn´t put a turret with 360 degree movement on a truck if it can´t use that feature.

GarryB wrote:Only see it fire forward and to the rear... will be interesting to see it fire to one side or the other...


Regarding the O... a Russian speaker could help perhaps with access to the original text?

it's when top brass sees firing howitzer and says Ooooo!      


And more seriously AFAIK  "O" is a letter assigned to a stage in, as they call, "Unified system for design documentation" process.  
"For products developed by order of the Ministry of Defense, the list of design documents, on which a letter must be affixed, is agreed with the customer.

The procedure for assigning letters to design documents is determined by GOST 2.103-68. Development stages (letters are given in the table). Although there are no explicit references to this standard in the CACC and the Unified Business Regulation System, we believe that in order to assign a letter to a document, it should be guided by it."

"O" is described as:

"Correction of Design Document  based on feedback from manufacturing and preliminary testing of a prototype (experimental batch)"





here you can enjoy better desc

https://philosoft-services.com/blog/wordpress/archives/236

marcellogo wrote:

THAT'S is the hard part, a tracked one have a lower sitting centre of gravity and tracks absorb well lateral movement, while a wheeled one risk to flip over.

Tactically however it is not so important to have a 360° for a long range artillery piece using scoop and scoot tactics firing some hundreds of meters farter or nearer from an objective  is perfetly feasible, being able to fire +/- 60° both forward an into rear would be more than enough in all tactical situations.

but wheeled howitzer is not going to fire from wheels      isnt it?

There are hydraulic stabilizer legs for every truck based platform.

GunshipDemocracy wrote:

marcellogo wrote:

THAT'S is the hard part, a tracked one have a lower sitting centre of gravity and tracks absorb well lateral movement, while a wheeled one risk to flip over.

Tactically however it is not so important to have a 360° for a long range artillery piece using scoop and scoot tactics firing some hundreds of meters farter or nearer from an objective  is perfetly feasible, being able to fire +/- 60° both forward an into rear would be more than enough in all tactical situations.

but wheeled howitzer is not going to fire from wheels      isnt it?

There are hydraulic stabilizer legs for every truck based platform.

Yes, I didn't say that it's impossible, only much more difficult to achieve such kind of performance in a wheeled vehicle.

Fact itself that they need stabilized legs is a proof of it as many tracked ones didn't have them anymore.

Now, if they are needed just to achieve 360° coverage it would be an excellent news.

GunshipDemocracy wrote:

GarryB wrote:Only see it fire forward and to the rear... will be interesting to see it fire to one side or the other...


Regarding the O... a Russian speaker could help perhaps with access to the original text?

it's when top brass sees firing howitzer and says Ooooo!      


And more seriously AFAIK  "O" is a letter assigned to a stage in, as they call, "Unified system for design documentation" process.  
"For products developed by order of the Ministry of Defense, the list of design documents, on which a letter must be affixed, is agreed with the customer.

The procedure for assigning letters to design documents is determined by GOST 2.103-68. Development stages (letters are given in the table). Although there are no explicit references to this standard in the CACC and the Unified Business Regulation System, we believe that in order to assign a letter to a document, it should be guided by it."

"O" is described as:

"Correction of Design Document  based on feedback from manufacturing and preliminary testing of a prototype (experimental batch)"





here you can enjoy better desc

https://philosoft-services.com/blog/wordpress/archives/236


.

Thanks very useful.

THAT'S is the hard part, a tracked one have a lower sitting centre of gravity and tracks absorb well lateral movement, while a wheeled one risk to flip over.

The wheeled one has stabilising jacks, so I assume despite not showing it that it can shoot 360 degrees. Recoil when firing looks very minimal on the wheeled model so I suspect it is no worse at different angles.

being able to fire +/- 60° both forward an into rear would be more than enough in all tactical situations.

Exactly... worst case scenario is not that bad anyway... certainly no worse than the 2S5 tracked versions angle limitations.... it has a 30 degree range of traverse it seems... but physically for the gun above to fire forwards and to the rear it can clearly traverse at least 180 degrees without needing to see it actually do so...

O behave... GD... thanks for the solution and description... makes sense now.

Now, if they are needed just to achieve 360° coverage it would be an excellent news.

The video above shows it firing forward and to the rear and the minimal movement during firing to me suggests they can probably shoot 360 degrees...