2S38 Derivatsiya-PVO 57-mm SPAAG

The 6km might be the range of the 57mm grenade launcher and perhaps is ballistic range for the HE rounds.

The 57mm gun will have different ranges for different targets...



So 6km for targets on the ground and 8km for air targets for that setup.



And this one that suggests the air burst and guided rounds can be used out to 15km against some targets...

Smart fuses would detect the impact and penetration and set off the HE charge after the round has penetrated into a cavity as an APHE type round.

The laser fuse will be in the tail and could be set off by laser beam anywhere along its flight path.

It is very very clever... they already had cheap simple air burst 40mm grenades where a small charge explodes on impact and blows the grenade back up into the air and the main charge is detonated at 1.5-2m in the air, so instead of leg and lower body wounds from grenade fragments you get head and upper chest wounds which are far more lethal.

The US solution was a laser range finder and ballistics computer on the grenade launcher with a fuse setting coil over the muzzle that set the grenade fuses as they fired. The problem was precision... the timers in the grenades themselves had to be very very precise to be of any use, which made each grenade rather expensive and the whole idea too expensive even for the US to use.

The US solution however allowed flying targets to be engaged whereas the Russian system needs to impact the ground near the target.

Using lasers to set off the grenades means it can be cheap and mass produced... and fitted to a 40mm grenade launcher means airburst rounds become affordable... a 40mm grenade has plenty of volume for rear mounted fuse and propellent, centrally mounted HE charge and sides and front mounted fragmentation... though I would think a forward mounted cup with ballbearings that are projected forward in a cone shaped pattern of fragments like a remotely fired shotgun would be best... with a known shape and pattern for the fragments you could automate the remote weapon station with the 40mm grenade launcher and have it direct grenades towards small drones which probably could not be detected outside the 2.5km range of the grenade launcher anyway.

It could also be used against ground targets trying to infiltrate or attack the air defence systems and would compliment a 57mm gun battery.... put some Bulat and Kornet and Pine missiles on the vehicle with the 40mm grenade launcher and you have an awesome anti drone vehicle...

Bigger shells are easier to improve as there is more volume for stuff and even fins to steer etc.

For instance... instead of a 76.2mm gun, you could use a 152mm artillery round with a base mounted laser receiver as used with Kornet and Bulat ATGMs with steering rear fins and the same laser receiver could be used to set off the main charge which could be 5kgs of HE and 35kgs of steel cubes and ball shrapnel.

Using it out to 20km or so, you could use it against aircraft... and to pretty high altitudes as well.

I would think the 100mm shell fired by the medium velocity rifled gun of the BMP-3 would be an interesting base model for an anti IFV round using an APFSDS round like the 57mm grenade round used but obviously with more propellent and higher pressure barrel, but most of the time it would fire a good HE round and missile.

Having different weapons for different weights just expands the logistics burden and makes things more expensive, often without adding flexibility or capability existing weapons could not already achieve.

A High pressure 120mm rifled gun using all the same shells and mortar bombs they use on their 120mm gun/mortar, but with an added APFSDS round as well could be interesting as a lower recoil round similar to the 125mm but for lighter vehicles and less well armoured targets...

That image looks familiar LMFS... perhaps scroll this page up a bit...

What I was trying to say about calibres is each one has a job but sometimes they lose their effectiveness.

With the BMP range of vehicles they started with a 73mm gun because of deficiencies with the AT-3 ATGMs which couldn't hit a tank target within 500m, because it took that long for the system to gather the missile under control and for the operator to get the missile onto line of sight ready to hit a target.

That meant the BMP-1 had to have a main gun that could penetrate the frontal armour of a western tank. The 73mm round it fired was essentially a super heavy RPG-7... in fact it was an SPG-9 rocket with slightly less propellent because it is fired from an enclosed gun instead of an open tube recoiless rifle.

Anyway come time for the BMP-2 the new ATGMs had a dead zone of 20-25 metres so the main gun could be dedicated to shooting enemy BMP like vehicles, which is what it is for.

It was found however that the high velocity 30mm cannon was very good at some things and not so good at others so both the BMPs were used together where their different guns complimented each other.

That is why the replacement BMP-3 replaces the 2A42 30mm cannon with a 2A72 30mm cannon for use against enemy light armour and also the 100mm rifled gun with a HE round and an ATGM replaces the 73mm gun and the external ATGM launcher.

The problem today is that the 30mm round is getting a little small and is now marginal on enemy BMP type vehicles, so the solution is to increase calibre.

The gun is also used for anti aircraft use as well but ironically the 30mm round is OK for aircraft including helicopters where it is still every bit as effective as it used to be, but drones are tiny and you would need to fire thousands of rounds to assure a hit, though airburst shells could solve that though.

One solution is to go to a larger calibre and in this case there seem to be two excellent solutions.

This vehicle (2S38) uses the same round as the S-60 AA gun. It offers good shell weight and good velocity and enough space for a decent warhead but also guided rounds or an effective APFSDS round too as well as a good smart fused APHE round.

It is ideal for anti aircraft use and can be used against ground armoured targets too if need be (traditionally Soviet AA gun vehicles are used in the ground to ground role too).

The second solution is the new 57mm grenade launcher. Just looking at the round itself:



You can see just using your fingers that the width is about 60mm and the entire length of the whole round is just over 5 calibres, which means 60 x 5 = about 300mm.

In comparison the 30mm cannon they use is a 30 x 165mm round, so half the length in terms of propellent case and rather narrower too.

As you can see from the above image the tiny stub propellent case on the HE round is very small much smaller than the propellent case for the 30mm round, but that is only because this is a HE round and muzzle velocity is not important.

The APFSDS round will be the same length as this whole round but instead of a tiny propellent stub and a huge HE projectile it will be a very long shell case with lots of propellent and a metal dart that is much longer and much heavier than anything you could fit into a 30mm cannon shell and with much more propellent pushing it down the barrel at much higher speeds.

With this combination of heavy long fast APFSDS round and long heavy HE round, the 57mm grenade launcher offers the opportunity to replace the 30mm cannon and the 100mm rifled gun on the BMP-3 with a weapon with better penetration than the 30mm and a good HE round that can be carried in much greater numbers and fired at a much higher rate if needed.

One 57mm grenade wont be as powerful as one 100mm shell... but a burst of 3-4 57mm grenades will be more effective.

Now they could have skipped the 57mm calibre and gone for a 76.2mm weapon or something even larger, but the smaller lighter 57mm guns will get the job done with smaller lighter ammo that can be carried in larger numbers.

The Russian Army don't really use 76.2mm guns any more, the smallest weapons they use will be 82mm mortars and 100mm guns, but the Russian Navy does use 76.2mm guns and the technology and design ideas used in the upgraded 57mm ammo for the 2S38 will almost certainly be used in other calibres in the Army and Navy to improve the performance of guns in service.

During WWII at the start of the war the Soviets had a decision to make... fit their brand new T-34 with the new 57mm high velocity gun that could take out Panthers at 1,000m at a time when there were no Panthers and Tigers on the battlefield, or use the 76.2mm gun with progressively longer and longer barrels that were effective against all the vehicles the Germans used at that time.

The main reason they chose the 76.2mm gun was because its HE round was much more effective, and tanks actually used HE round against troops and fortified positions much more than they fired at tanks most of the time.

Note the 57mm anti tank gun I am talking about is not the same as the 57mm AA gun called the S-60, the AT gun ammo had a longer shell case with more propellent. It was a 57 x 480mm round compared with the 57 x 347mm...

Drones are easy targets when you can detect them on time. As easy as helicopters.

No they are not.

A 30mm cannon like Tunguska is designed to send up a spread of shells because between the time the rounds are fired and when they impact the target is several seconds so there is a time gap where the target could speed up or slow down or climb or descend or turn left or right and the shells directed at where it was going to be end up missing completely.

Against a helicopter sized target you have a significant area to aim for, so a burst of 100 or 200 rounds means you should connect with a few of those rounds and considering most are powerful enough to bring the helicopter down then a 30mm cannon system is effective out to reasonable distances.

At 4km the spread of the rounds will be rather huge, so a long burst of rounds is needed to get the sort of concentration of projectiles needed to assure a kill... the wide spread of rounds makes it even harder for the target to evade getting shot down with manouvers.

A drone target in comparison is tiny and even if it is stationary the 30mm cannon shells actually have to make contact to actually explode... at more than 2km the chances of a direct hit are close to zero.

With airburst rounds instead of trying to hit the target directly with 100-200 projectiles, you would be trying to hit the target with thousands of fragments from a few rounds being fired which is much more effective and efficient and cheaper and quicker so more targets can be engaged.

Air burst rounds on their own are vastly more expensive but actually have a chance of damaging an enemy.

Ironically against a drone a small Airburst round like a 30mm is viable because they are fragile... against an Apache the fragments would damage the side canopy and possibly the optics or weapons on their pylons, but most of the time full calibre AP and HE rounds would be more effective.

Most other helicopters like western transport helicopters are fragile so HE Frag and airburst should be fine.

The advantage of 57mm shells is that the fragments can be much bigger and more effective, and be delivered effectively to much greater ranges.

For most countries drones are going to remain a serious problem... first and foremost because most are plastic with electric motors so little radar or IR signature most of the time you wont detect them in the first place.

One of the main reasons for their shift to 57mm calibre rounds is the ability to make better airburst rounds for use against cruise missiles and drones.

The other reason is the propellent case capacity to fit guided rounds and decent APFSDS rounds rather more capable than could be fitted into the much smaller 30 x 165mm cannon round.

Note Armenia suffered because it underestimated the problems of shooting down drones.... being on the receiving end is what made Russia respect drones and invest in both defeating them and making their own.

They don't really need murder bots, but they are developing a whole new range of custom designed weapons for them that few other countries have bothered to do.

You could say they are behind the US in drones in general but they are rapidly closing the gap and seem to have a range of custom designed weapons ready for use for their drones... while the US use enormously expensive weapons like Hellfire on their expensive drones... maybe they didn't get the memo.