2S25 Sprut-SD

GarryB wrote:
If you want metre precision it has to be a very precise and accurate timer, and to detonate a round above a trench does require very precise time keeping.

That is what killed the US 20mm automatic grenade launcher/rifle grenade, because the timers in the grenades were just too expensive.

(in comparison the Soviets had a airburst grenade for their underbarrel grenade launchers for four decades, but it cheats... it doesn't use a precise timer and ballistic computer... it merely uses a small bounding charge and short fuse to the main charge like a bounding mine... simple and cheap for use against ground targets but no good for air targets of course.).

I think you're comparing apples with oranges here. The fuse for a 125 mm shell is about the size of a 20 mm grenade. It also doesn't have to be as cheap.
Without these constraints, it becomes much easier to make a more precision time keeping device.

GarryB wrote:
It was no good against a flying target or fast moving target, but against those there is a guided missile round.

For a fixed target like a trench or a group of enemy troops behind a solid wall, it was very good.

With the proliferation of fire and forget weapons the capability to snap shot at just detected threats only becomes more important. As it is, you would have a delay of 2-3 seconds for the programming sequence before you can load - that is if you didn't battle carry.

GarryB wrote:
I would presume the radar would work like the laser, with an optical sight pointed at the target in question and ranged using radar waves... then distance added or deducted from the range and then the round fired... the radar tracking the out going round and when it reaches the set distance a radio command is sent to set off the round... or something along those lines.

The issue is a radar that is capable of tracking very small, very fast projectiles at low altitudes would be a very expensive system. Think Khrizantema.

GarryB wrote:
That is interesting because the old HE Frag shells the fuse was in the nose and the fragments were essentially the walls of the HE shell so most of the fragments go sideways and straight up and straight down... such a round design is rather better for mortar or Howitzer fire with plunging shells where the shell sides create an even circular pattern as it comes down vertically.

Some sort of forward facing array of fragments that blow forward like a shotgun blast would be rather more effective against enemy troops in the open... just range the front guy and take 20m off the range and fire...

That's because it is. The old 125 HE shell was the 122 mm shell with a finned tail.

Show me a single video of Russians using ainet shells in ukraine. Every single video ive seen shows them only using rounds that detonate when hitting the ground.

I have not seen any videos of Russian TOR or Pantsir or Viking SAMs being used in the Ukraine which is definitive evidence they have never been used in the conflict in the Ukraine?

The fuse for a 125 mm shell is about the size of a 20 mm grenade. It also doesn't have to be as cheap.
Without these constraints, it becomes much easier to make a more precision time keeping device.

But the real point is that the timer they used for the 125mm HE FRAG shell was not precise enough to get the flight time accuracy they wanted, which made it less useful than it should have been. To get the level of accuracy they needed the alternative would have been bigger and also much more expensive so they didn't bother pursuing it.

When it became apparent that they needed a precise timer for 30mm HE rounds which is much smaller they realised that accurate timers inside the fired round no longer were practical, so they shifted the timer to the vehicle instead of the ammo and replaced the timer in the round with a receiver to command detonate the round... initially a laser beam command, and later a radar based radio command signal to work through dust and smoke on the battlefield.

The receiver was much smaller and cheaper than the timer could have been so it made sense to use it... and I hope they are using the same on this 125mm system for the Sprut.

Air burst rounds are vastly more effective... even just 40mm under barrel grenades with a bounding charge setting off a fuse the sets off the main charge at a height of 1.5 to 2 metres is vastly more effective than a 40mm grenade with a single much larger main charge set off on impact.

When fired at troops in an open field the impact grenade causes leg and lower body injuries, which can slow down an attacking force and is effective, but the airburst rounds cause head and upper body wounds where kills are much more common... by a wide margin.

For use against some target types air burst rounds are vastly more effective and useful, and the advantage of ANIET is that it uses a special fuse but the shell is just a standard shell.

A specialised shell designed to direct fragments in useful directions makes even more sense and a tail mounted sensor to set the fuse after being fired is even more useful... especially if it can be scaled down to 30mm and 40mm and 57mm and any other calibre too.

The ammo would be cheap and the extreme precision can come from the fire control system of the vehicle which are generally rather sophisticated anyway leading to precise detonations.

Being cheaper means you can use it as a standard round of ammo rather than as a special round.

With the proliferation of fire and forget weapons the capability to snap shot at just detected threats only becomes more important. As it is, you would have a delay of 2-3 seconds for the programming sequence before you can load - that is if you didn't battle carry.

With guns that can fire a variety of round types if you have a round loaded then you had better hope it is suitable for the target you next come across.

Most of the time the gun would be empty to start an engagement. With ANIET the fuse is set as the round is loaded, but you need to find the target and determine range and therefore flight time, which the gunner can then adjust and adjust his aim slightly high and then load the round (fuse is set as it is loaded) and then fire.

The time between fuse setting and firing can be very very short if that is important.

But with radar command detonation you can track the target and the round and when they get as close as they are likely to get the detonation command could be sent to explode the round. All the precise timers and accurate fire control systems on the vehicle can be as precise as you can make them because you reuse them over and over with every round.

The issue is a radar that is capable of tracking very small, very fast projectiles at low altitudes would be a very expensive system. Think Khrizantema.

You could put a circle of corner reflectors around the rear rim of the round with the radar receiver in the centre... that shell might look like a small car to your radar.

limb wrote:

The Russians use new HE-frag shells with preformed fragments. If the fuze triggers early you get a shower of fragments from the front section, late the sides. It even seems based on gun cams from Syria and Ukraine plunging fire with Ainet fuze shells is the favored tactic against infantry.

Show me a single video of Russians using ainet shells in ukraine. Every single video ive seen shows them only using rounds that detonate when hitting the ground.

Remember a video filmed by Ukrainians being shelled which showed it quite clearly

A shell detonated maybe 5-10m above the ground and the soldier filming was hit by shrapnel