2S19 MSTA-S 152mm

Suppress artillery and mortar fire, tanks and anti tank fire (ATGM), electronics (drones? and comms nodes), etc etc... sounds like they are optimising them for conflicts like Syria to take on a wider range of targets as a lower cost alternative to air strikes...

Latest Msta-S artillery systems arrive for troops in Russia’s south

The upgraded howitzers feature a new automated fire control system, a higher rate of fire and the possibility to use digital electronic maps to accelerate finding positions on the terrain, according to official data

MOSCOW, March 16. /TASS/. The latest artillery systems arrived for the Southern Military District’s 49th all-arms army, the District’s press office reported on Monday.
Read also
Troops fire Msta-S artillery guns to strike enemy command posts in Urals drills

"Two artillery batteries have been reamed with the improved 152mm 2S19M2 Msta-S self-propelled artillery guns capable of firing Krasnopol precision guided munitions," the press office said in a statement.

"The Msta-S artillery system has considerable design differences from the previous modification," the press office stressed.

Specifically, the upgraded howitzers feature a new automated fire control system, a higher rate of fire and the possibility to use digital electronic maps to accelerate finding positions on the terrain.

Msta-S self-propelled artillery guns can also "fire high-explosive fragmentation and rocket-assisted projectiles — jammers," the press office said.

https://tass.com/defense/1130667

A question:  do naval guns have the same range and rate of fire of their land equivalent?
I mean comparing as an example a 130mm naval gun with a 130 mm artillery gun?

It is because I read about a 30 km range for the 152mm gun 2S19 MSTA, and longer ranges for smaller naval guns (also because there are currently no naval guns in service bigger than 130mm).

Tthe main problem is the different calibres used and the different guns for each calibre.

The 152mm calibre has been used by the Soviet Army since before WWII, but different 152mm guns can use different types of ammo... a bit like 7.62mm rifle calibre ammo effectively the 7.62x25mm (Tokarev) pistol and SMG ammo from WWII is the same calibre as the 7.62 x 39mm rifle, assault rifle and LMG calibre (SKS, AK, RPK respectively), and the 7.62 x 54mm R rifle and LMG and MMG calibre also uses the same diameter bullets but the shell case contains different amounts of propellent leading to very different performance... and it is the same with 152mm artillery ammo in Russia.

Also important is that some guns are howitzers and some are guns, and different weapons have different barrel lengths which also effects performance like range.

The Soviet Navy during WWII had a wide range of gun calibres that are too numerous to list, but after WWII they settled down on fewer and fewer types... 30mm gatlings largely replaced the various 37mm and 45mm anti aircraft guns, while in larger calibres they had 57mm and 76.2mm and 100mm as well as 130mm guns and the occasional 152mm gun... but the current generation they have 100mm guns the size and weight of the old 76.2mm guns, 130mm guns the size and weight of the old 100mm guns and the 152mm guns are no longer used.

The Soviet Army no longer uses the smaller calibres for artillery and largely settled on 122mm and 152mm guns as normal standard, while 125mm high velocity guns are used as tank guns and they have a 152mm replacement that is developed but not deployed and they are gradually withdrawing the 122mm guns in favour of 120mm gun/mortars.

Generally naval guns can be bigger calibre and longer ranged because weight is not important and recoil is very efficiently absorbed by water.

The naval version of Coalition might be a twin gun arrangement simply because there is plenty of space and capacity for an enormous amount of ammo... turret rings on ships can be as big as you want to there is plenty of potential to absorb recoil and fit all sorts of auto loading mechanisms.

Right now the Russian Army has the range advantage because they still retain 203mm guns with roughly 50km ranges, and of course the Coalition 152mm guns with 70km range and soon mini shells with 180km range are possible too, but while 203mm land guns are a niche weapon that might only be used when its specific capacity is needed, a naval model might be useful for a landing ship or helicopter carrier for example... a 100km range with a large projectile would be useful all weather day night fire power.

The Soviet fleet reactivated the Sverdlov class to use their 152mm guns for fire support for landing operations, but they never really had ocean going landing ships able to make proper landings away from the reach of Russian land based air power, so with these new helicopter carriers they are building they might start improving their gun artillery capacity to support landing operations cheaply and simply.

The new Russian ships have corvettes with 100mm guns where previously they had 57mm or 76.2mm guns, while their frigates have 130mm guns where previously frigates had 76.2mm or 100mm guns, so for their destroyers the question is will they use the 152mm guns developed together with the Russian Army? I would expect so, but do they use those same 152mm guns for Cruisers as well or go for an upgraded 203mm gun for cruisers?

The point is that any money spent developing 203mm guns and new long range and accurate ammo types can be used with army equivalents so costs can be shared and certainly for the Navy a good 203mm gun would have serious benefits without many of the problems much bigger guns can introduce... 203mm is still reasonably manageable and in terms of performance a 110-130kg shell is rather more effective against bunkers and strong points than any number of 50kg 152mm shells...

New ammo for Coalition (which also has a longer gun barrel and more propellent options) has been tested to 70km and what I presume to be a reduced payload round has been suggested with a range of 170-180km... for light targets. Such rounds should be compatible with a naval gun mount in 152mm calibre too of course...

Msta-S self-propelled guns hit targets at distance of 15 km during Kavkaz exercise

The Ministry of Defense has received another batch of Msta-S self-propelled artillery mounts

https://en.topwar.ru/183592-minoborony-poluchilo-ocherednuju-partiju-samohodnyh-artillerijskij-ustanovok-msta-s.html

Artillery of the future: modernization of the ACS 2S19 "Msta-S" and its prospects

The Russian ground forces are armed with several types of self-propelled artillery units with different characteristics and capabilities. To date, the most widespread vehicles of this class are ACS 2S19 "Msta-S" of a number of modifications. They will have to continue serving for a long time, and for this a deep modernization program has been launched and is being successfully implemented.

Modernization processes

"Msta-S" entered service in the late eighties. However, the production of such equipment in small batches has been carried out since the first half of the decade. Later, a full-fledged series was mastered, intended for the rearmament of the Soviet army. After the collapse of the USSR, the existing equipment was divided between the new states, and Russia continued production. According to known data, at least 1100 self-propelled guns of several modifications have been built to date.

The development processes of the basic self-propelled guns started immediately after being put into service. During the nineties, the 2S19M project (aka 2S33) was developed, which provided for the introduction of a number of new devices. Its updated version, 2S19M1 in the second half of the two thousandth, reached the point of adoption. Self-propelled guns of the "M1" version were rebuilt from the existing machines in the order of repair and modernization.

Upgraded self-propelled gun 2S19M1

Then work began on a new modification - 2S19M2 "Msta-SM". Various updates were proposed again, affecting controls, weapons, etc. In 2012, the modernized ACS passed state tests and was recommended for adoption. The following year, the industry began to supply equipment of this model. Msta-SM can be built from scratch or rebuilt from the equipment of previous modifications.

According to The Military Balance 2021, the Russian army currently operates 820 Msta-S self-propelled guns of all major modifications. The authors of this publication counted 500 combat vehicles of old modifications 2S19 and 2S19M1, as well as 320 modern 2S19M2. In addition, 150 self-propelled guns were put into reserve. Thus, in terms of their number, the 2S19 family machines have by now bypassed the older 2S3 "Akatsia" self-propelled guns with a gun of the same caliber. The active fleet of such equipment includes 800 units, although there is a reserve of 1000 units.

Production rates

The release of the updated ACS 2S19M2 was mastered by the Uraltransmash enterprise with the participation of a number of other organizations supplying new components and assemblies. Thus, the production of a modernized 152-mm howitzer is carried out by the Barricades plant. The production line was prepared in 2012, at the same time as passing government tests.

Modern self-propelled guns 2S19M2 "Msta-SM"

As reported by the Ministry of Defense, the first batch of modernized self-propelled guns entered the troops in June 2013, 35 units. such equipment was transferred to one of the artillery units of the Southern Military District. Soon there were reports of the use of updated machines during the exercise.

In the future, production maintained the required pace and ensured regular deliveries of new and modernized equipment to the troops. For example, plans for the past year provided for the delivery of more than 35 self-propelled guns "Msta-SM". As far as we know, they were successfully carried out and ensured the rearmament of one of the units.

On May 31, the state corporation "Rostec" announced the completion of construction and the shipment of the next batch of self-propelled guns 2S19M2. This equipment was manufactured as part of the state defense order for 2019-21. and was built on time. The number of armored vehicles built, as well as the place of their future service, is not specified.

Most likely, the process of production and modernization of equipment will continue in the future. Thanks to such processes, modern ACS "Msta-SM" over the next few years in their number will be able to catch up with the equipment of previous modifications, and then bypass them. Even with the protection of the total number of self-propelled guns at the same level, this will significantly increase the potential of artillery as a whole.

Technical Issues

The 2S19M2 project provides for a comprehensive modernization of the basic armored vehicle with the replacement of some of the components, due to which an increase in all main characteristics and a number of new opportunities are provided. New systems and units were introduced without changing the architecture of the machine, as well as with minimal impact on its exterior.

The chassis of the ACS remains the same and retains the original set of nodes and the same characteristics. At the same time, a new diagnostic system has been introduced, which provides the driver with up-to-date data on the condition of the car. This to a certain extent simplifies the operation and maintenance of self-propelled guns.

At the same time, the main modifications of the Msta-SM project affect the equipment of the fighting compartment. The self-propelled gun receives an improved 152-mm 2A64M2 rifled howitzer. Due to a number of innovations, the rate of fire has been increased to 10 rds / min. and improved other parameters.

Modern equipment with a high degree of automation is used. ACS received navigation devices with the ability to use digital maps and receive satellite signals. In the fire control system, some devices have been replaced, and weather sensors and other devices have been introduced. After such an upgrade, the self-propelled gun shows increased accuracy and firing efficiency. Also, there was a "squall of fire" mode, obtained due to the modern MSA and high rate of fire. If necessary, fire control can be carried out remotely from a battery command post.

There are certain ways for the further development of self-propelled guns that can provide a new increase in performance. In the recent past, the management of Uraltransmash talked about the possibility of creating a new generation of ammunition. At the same time, plans were announced for a new improvement in operational characteristics.

Artillery of the near future

ACS 2S19 of all modifications are qualitatively superior to the older "Acacia". By now, a quantitative superiority over all other 152-mm self-propelled systems has also been ensured. At the same time, the production of new equipment and the modernization of existing machines continues, which has obvious positive consequences.

A completely new self-propelled gun 2S35 "Coalition-SV" has already been developed and is being prepared for a full-scale series. However, the production of a large amount of such equipment will take a lot of time, and therefore the Msta-S of various modifications will still retain its place in the army. Over the next few years, it will remain the most massive and effective self-propelled gun of the Russian army. It can be expected that during this period, at least most of the available equipment will be upgraded to Msty-SM.

In the future, after receiving a sufficient number of new "Coalition-SV", the army is unlikely to quickly abandon the older 2S19M1 / 2, although other types of equipment should be expected to be removed from service. The mixed composition of self-propelled artillery will again allow obtaining the maximum possible characteristics and capabilities, as well as providing high flexibility of use for solving a variety of fire missions.

Thus, the processes observed now are of particular importance for the near and distant future of army artillery. The gradual replacement of older 2S19s with modern 2S19M2s does not just ensure the preservation of equipment in service and increase its characteristics. Due to these processes, a large reserve is also created, which will determine the appearance and capabilities of artillery units in the near and distant future.

https://covid36qdxuptbodqslievhsl4-ac4c6men2g7xr2a-topwar-ru.translate.goog/183636-artillerija-buduschego-modernizacija-sau-2s19-msta-s-i-ee-perspektivy.html

Defense firm delivers latest Msta-S self-propelled howitzers to Russian troops

The defense contractor fulfilled the defense procurement plan on time

YEKATERINBURG, November 10. /TASS/. Uraltransmash (part of the Uralvagonzavod defense manufacturer within the state tech corporation Rostec) produced and delivered new 2S19M2 ‘Msta-S’ self-propelled howitzers to the Russian troops under the defense procurement plan, the Company’s press office told TASS on Wednesday.

"In creating the 2S19M2 ‘Msta-S’ weapon, the rate of its aimed fire was improved to 10 rounds per minute, its aiming accuracy was increased and the artillery burst mode was introduced to strike a target with five shots at a time and exit the position. Also, the crew habitability conditions were improved," the press office quoted Uraltransmash CEO Dmitry Semizorov as saying.

The defense contractor fulfilled the defense procurement plan on time, the press office stressed.

The 2S19M2 self-propelled howitzer is a modern combat vehicle developed with the focus on its improved operational performance and higher reliability. The weapon is fully supplied with spare parts and accessories and was approved by the Defense Ministry’s acceptance office.

https://tass.com/defense/1359801

A batch of self-propelled howitzers entered the troops of the Western Military District, in total, the military received 12 new Msta-SM2 self-propelled guns.

https://en.topwar.ru/191798-partija-samohodnyh-artillerijskih-ustanovok-msta-sm2-postupila-v-vojska-zvo.html

https://tass.ru/ekonomika/15984121

"Uraltransmash" ahead of schedule handed over to the Ministry of Defense of the Russian Federation a batch of modernized howitzers "Msta-S"

The decision was made as part of the implementation of the state defense order in 2022

YEKATERINBURG, 7 October. /TASS/. Uraltransmash (part of the Uralvagonzavod concern, part of Rostec) delivered a batch of 2S19M2 Msta-S self-propelled howitzers to the Ministry of Defense ahead of schedule after a major overhaul with modernization under the state defense order. This was reported to TASS in the press service of the enterprise on Friday.

"As part of the implementation of the state defense order in 2022, Uraltransmash sent a batch of 2S19M2 Msta-S self-propelled howitzers ahead of schedule after a major overhaul with modernization to the Ministry of Defense of the Russian Federation. The howitzer was equipped with an automated guidance and fire control system. When bringing the ACS to the level of 2S19M2, the aiming rate of fire up to 10 rounds per minute and pointing accuracy. A fire raid mode has also been introduced, which allows one gun to hit a target with five shots at once, and then leave the firing position. In addition, the living conditions of the crew have been improved," the report says.

The 2S19 Msta-S self-propelled howitzer has several unique tactical and technical characteristics, including a high rate of fire, the ability to fire various types of projectiles, as well as the ability to quickly occupy and leave a firing position.

Found a nice little gem:



I believe this is the first footage of I've seen with the semi-autoloader in operation, and in combat even. Previous footages of Msta-S always had the crew load manually, presumably as practice in peacetime.

I call it semi-autoloader because two human loaders either side of the gun are in charge of loading the propellant charges to a waiting tray. A bustle conveyer chain rams the shells to the other tray.

Quick and simple, and more importantly, safe. No one's getting behind a gun to shove charges anymore - unlike some "advanced" howitzers out there.

Is the Msta M2 in production?

It should be, considering they're in a war?

10 rpm. I forgot to mention the two loaders are also responsible for setting the fuzes and charges (the metal case have modular charge bags inside you can load/deload). For performing MRSI the charge man would have pre-set charges at the ready he just needs to load in the correct sequence.

Arguably the best SPH in the market. Between the reveal of the performance of MSTA-SM2 and the fact that Russia outproduces NATO and their butt buddies 3-1 in artillery shell a lot of countries that bought into the 155mm meme (ahem, India) are probably kicking themselves hard from buyer's regret.

Reading up on 2S19M2 improvements, have seen the consistent claim online that unlike the original, the M2 has a "new 2A79 152 mm/L60 ordnance that has improved ballistics."

Except I can't see any evidence this is the case? The cannon on every M2 model I've ever seen is the exact same length as the 2S19's 2A64 152mm/L47 - and as far as I can see, is the same gun. Anyone know where this came from?

Vympel wrote:Reading up on 2S19M2 improvements, have seen the consistent claim online that unlike the original, the M2 has a "new 2A79 152 mm/L60 ordnance that has improved ballistics."

Except I can't see any evidence this is the case? The cannon on every M2 model I've ever seen is the exact same length as the 2S19's 2A64 152mm/L47 - and as far as I can see, is the same gun. Anyone know where this came from?

From what I understand the original design of the M2 was supposed to include the longer gun. But that was scrapped between the design and production stages.
Which is really lame to be honest.

lancelot wrote:

From what I understand the original design of the M2 was supposed to include the longer gun. But that was scrapped between the design and production stages.
Which is really lame to be honest.

Agreed. I guess they figured they'd get a much superior gun with 2S35 Koalition, except the Ukraine war has illustrated how they would've been better off fitting a new gun to their more numerous pieces, sooner.

It is more than just... this gun is better so use it.

They have probably large numbers of guns in theatre and making guns means building a vehicle with a gun fitted but also making and supplying replacement barrels.

When you are firing tens of thousands of shells per day with hundreds of guns then barrels are going to need to be replaced on a regular basis and having different barrels swapping in an out on the front line would be a pain in the arse... especially when you consider how artillery actually works.

Most shots will not be at max range for the Russians. Most shots will be at front line targets that need softening up, or an advancing enemy force of infantry on foot and ground based armour where you don't fire one or two shots and then move... you fire a barrage of shells and then you move and reload and fire another barrage of shells... which is why the Russians are firing 10s and 100s of times more shells than the Ukrainians who might have single vehicles sneaking around firing a shell or two and then running.

Extra range for most Russian guns doesn't mean anything at all because if targets are detected that need to be hit deep behind enemy lines then the Russians have an enormous range of options from Smerch and even late model Grad and Uragan and of course Malka (203mm), as well as attack helicopters and air delivered glide bombs and LMUR and a range of guided weapons from Grom-1 and Grom-2 and also Kh-38 etc etc... not to mention drones... their current batch of suicide drones reach 200km.

It is better to make existing barrels in large volumes and send in a few Coalition vehicles with new guns to get some real combat experience with them to see if they can get the job done and why could be changed to improve them.

Of course the pussies will cry that what if it gets hit or taken out... well this is war and that is a risk, but finding out what tactics work and what tactics don't work is actually more valuable than getting a longer ranged gun into service.

It is the tactics and way they are used that is the important thing as to how effective they will be and how safe they will be too.

Nothing is 100% safe in war.

GarryB wrote:It is more than just... this gun is better so use it.

They have probably large numbers of guns in theatre and making guns means building a vehicle with a gun fitted but also making and supplying replacement barrels.

When you are firing tens of thousands of shells per day with hundreds of guns then barrels are going to need to be replaced on a regular basis and having different barrels swapping in an out on the front line would be a pain in the arse... especially when you consider how artillery actually works.

Most shots will not be at max range for the Russians. Most shots will be at front line targets that need softening up, or an advancing enemy force of infantry on foot and ground based armour where you don't fire one or two shots and then move... you fire a barrage of shells and then you move and reload and fire another barrage of shells... which is why the Russians are firing 10s and 100s of times more shells than the Ukrainians who might have single vehicles sneaking around firing a shell or two and then running.

Extra range for most Russian guns doesn't mean anything at all because if targets are detected that need to be hit deep behind enemy lines then the Russians have an enormous range of options from Smerch and even late model Grad and Uragan and of course Malka (203mm), as well as attack helicopters and air delivered glide bombs and LMUR and a range of guided weapons from Grom-1 and Grom-2 and also Kh-38 etc etc... not to mention drones... their current batch of suicide drones reach 200km.

It is better to make existing barrels in large volumes and send in a few Coalition vehicles with new guns to get some real combat experience with them to see if they can get the job done and why could be changed to improve them.

Of course the pussies will cry that what if it gets hit or taken out... well this is war and that is a risk, but finding out what tactics work and what tactics don't work is actually more valuable than getting a longer ranged gun into service.

It is the tactics and way they are used that is the important thing as to how effective they will be and how safe they will be too.

Nothing is 100% safe in war.

To be clear I'm not talking about wartime, but when the M2's specifications were finalised. Its unlikely that when they were determining what the M2 would be equipped with they were thinking about a future SMO - they just didn't consider it necessary at the time to fit the proposed new gun, probably due to cost reasons. If they had procured the M2 from the start with the new gun any logistics issues would be ameliorated by its increased numbers.

GarryB wrote:Extra range for most Russian guns doesn't mean anything at all because if targets are detected that need to be hit deep behind enemy lines then the Russians have an enormous range of options from Smerch and even late model Grad and Uragan and of course Malka (203mm), as well as attack helicopters and air delivered glide bombs and LMUR and a range of guided weapons from Grom-1 and Grom-2 and also Kh-38 etc etc... not to mention drones... their current batch of suicide drones reach 200km.

It is better to make existing barrels in large volumes and send in a few Coalition vehicles with new guns to get some real combat experience with them to see if they can get the job done and why could be changed to improve them.

Of course the pussies will cry that what if it gets hit or taken out... well this is war and that is a risk, but finding out what tactics work and what tactics don't work is actually more valuable than getting a longer ranged gun into service.

The issue is that having short range artillery makes it highly vulnerable to cheap massed drone attacks. Personally I think they just need to build more of those 120mm wheeled mortars for the short range artillery fires. Those at least are cheaper to buy and can be mass produced more easily than something like the Msta. And the Msta should be upgraded with a longer barrel, so they don't lose a hard to replace tank chassis so easily.

To be clear I'm not talking about wartime, but when the M2's specifications were finalised. Its unlikely that when they were determining what the M2 would be equipped with they were thinking about a future SMO - they just didn't consider it necessary at the time to fit the proposed new gun, probably due to cost reasons. If they had procured the M2 from the start with the new gun any logistics issues would be ameliorated by its increased numbers.

Fair enough but sometimes a change is worse than the status quo.

If conflict breaks out in the middle of a transition from one system to another it can be more problematic than if you were not in the middle of that transition.

I rather suspect existing ammo is in bulk storage and mass production facilities were available and operating at an idle rate, which meant that a shift into high production was not difficult or painful.

If they had shifted to a new gun the new propellent would have been an issue... and if they couldn't produce it at the rate required... or more accurately they couldn't increase mass production to meet the new needs for the conflict then they would have had to go back to older weapons anyway... despite having spent extra money on the new systems.

It was the introduction of the T-34 and KV-1 when the Germans that invaded that shocked the Germans but it also created the problem that most tank units didn't have the new ammo that their new tanks required so a lack of anti armour shells limited the impact of the new vehicles at a time when they had their best crews ready to use them. When those troops got killed or captured or pushed back then new gear could not be trained on in the way the first soldiers could train on them, but they didn't get that chance either because the vehicles were relatively new.

Moving from T-26 and T-35 tanks to T-34s and KV-1s was a bit of a step.

In terms of artillery I think their existing stuff has shown its effectiveness time and time again and in terms of artillery volume and numbers is a quality of its own.

The issue is that having short range artillery makes it highly vulnerable to cheap massed drone attacks.

Russias new suicide drone has a range of 200km so there is no artillery that is safe from drones and that is a reality all armoured forces will need to get used to moving forward.

Ironically Russia is best placed to defend itself from the drone threat and I am pretty sure they would prefer to have shorter ranged artillery but proper air defence, than give that up for longer ranged artillery.

And to be clear HIMARS has a shorter range than Smerch and ATACMS is shorter ranged than Iskander and Russian artillery outnumbers Ukrainian artillery 10 to one in guns and 1,000 to one in ready to fire shells.

The claims of better range for western artillery simply don't add up because that would require special shells I suspect they don't have a lot of... so firing standard shells their range is not better than Malka.

Personally I think they should deploy more anti drone systems that can be used against ground targets too so they are dual purpose, and then use drones to hunt the enemy down man by man and kill them.

Equally in the air when the Germans attacked the Soviets were just transitioning from Polikarpov I-15 and I-16s to MiG-1 and MiG-3 and Yak-1 and LaGG-3s which were significantly better aircraft, that would be developed into even better performing aircraft as engines increased in performance and new weapons were added.

GarryB wrote:Equally in the air when the Germans attacked the Soviets were just transitioning from Polikarpov I-15 and I-16s to MiG-1 and MiG-3 and Yak-1 and LaGG-3s which were significantly better aircraft, that would be developed into even better performing aircraft as engines increased in performance and new weapons were added.

The MiG-1 back then wasn't considered to be terribly useful. It was basically designed as a high altitude interceptor and most combat took place at lower altitudes in the Eastern Front. For much the same reason as the Soviets didn't like the Spitfire, they didn't like the MiG-1 or MiG-3.

The Yak-1 was a decent aircraft, but it entered production kind of late, so it wasn't available in large numbers when the war started. It also required a whole new production process.

Hadn't they pushed Polikarpov aside it could have been that the I-180 would have entered production and it would have been available in numbers before the war started. It used much of the same resources as the I-16. So it would have been easier to gear up for mass production than the Yak-1.

I also don't quite get why they gave up on the I-17. Perhaps the V-12 engines that the Soviets had back then weren't good enough to make it a decent fighter. The MiG-1 is basically just a clone of the I-17 with a different engine.

Vympel wrote:Reading up on 2S19M2 improvements, have seen the consistent claim online that unlike the original, the M2 has a "new 2A79 152 mm/L60 ordnance that has improved ballistics."

Except I can't see any evidence this is the case? The cannon on every M2 model I've ever seen is the exact same length as the 2S19's 2A64 152mm/L47 - and as far as I can see, is the same gun. Anyone know where this came from?

They had a plan to use L/60 guns for the 2S19M2 in the interim while waiting for the 2S35 to finish its tests. But war accelerated the pace of the 2S35's development so its now entering active service and so the plan for upgunning the former just petered out. That's ok; Plans always change in the face of new developments - that's why its just a plan.

A new caliber gun also means new firing tables, which means retraining artillerists. The Koalitsiya has a robot do all the cool things between the gunner selecting the ammunition and pressing fire so its there's no issue at all with changing calibers.