Indirect Fires Modernization Project - C3/M777 Replacement

[FJAG]

Is it to late to ask Santa to gift us some new M119/118's for the Reserves?

I actually don't think we need them - we can continue to use clapped out C3s for saluting bases.

For operational artillery for an army of around 25,000 RegF and 30,000 ARes I see the following (which equates to two small expeditionary-capable armoured divisions, a larger homeland division and a general support division):

6 x SP regiments - 108 x 155mm SP guns plus 36 medium range UAV/LM launchers plus 6 x STA batteries
1 x light regiment - 18 - 24 x 155mm M777 plus 6 medium range UAV/LM launchers plus 1 x STA battery
6 x HIMARS regiments - 108 launchers plus 36 long range UAV/LM launchers plus 6 STA batteries
3 x STA regiments - 9 x STA/EW/MI fusion batteries plus 18 long range UAV/LM launchers
6 x AD regiments - 18 x mixed VSHORAD/SHORAD batteries
Plus an adequate number of training and tech spares.

Note that only two HIMARS regiments are allocated to the expeditionary armoured divisions. The other four are three: in the homeland division in an A2/AD role and one in the GS division that can go either way (my guess is homeland A2/AD and not expeditionary)

In total that needs about 10,000 gunners not counting sigs and MI or logisticians. We currently have just less than half of that in Reg and ARes gunners. If you want to arm Canada for a real war then you need to first provide the weapons that are needed. ARes forces will have to make a substantial contribution in all of these fields many of which do not need routine access to a firing range very often - maybe once per year - nor will they need full time soldiers during peacetime. Much of this works on simulation.

Eventually we'll have to think about an arty role in the field of several IAMD regiments.

 

[Colin Parkinson]

With a 25% availability rate

 

[MilEME09]

With a 25% availability rate

And this is why we need to establish a crown corp for critical items like arty barrels. Its in our strategic interest to be able to do it

 

[Colin Parkinson]

And this is why we need to establish a crown corp for critical items like arty barrels. Its in our strategic interest to be able to do it

Just keeping the SPG moving, much less shooting is going to overtax our crappy logistic support systems. Get the M119 asap. When you get your M777 and SPG, MLRS, SHORAD, then you can pack the surplus ones in grease as war reserve.

 

[FJAG]

Just keeping the SPG moving, much less shooting is going to overtax our crappy logistic support systems. Get the M119 asap. When you get your M777 and SPG, MLRS, SHORAD, then you can pack the surplus ones in grease as war reserve.

Why in the name of heaven would you go to a crappy interim pop howitzer rather than getting a proper system in the first place? Because of inadequate logistics? The proper solution is to get the logistics system ramped up to do the job as part of the acquisition program.

Let me simply say that we had no problem keeping several regiments of 109s on the road back in the 80s. Maintaining an SP howitzer isn't rocket science and it doesn't take a decade to train the techs or to set up a proper parts program. The problem is when an acquisition program starts cutting corners on the proper support systems. Honestly, I'd give up 50 gunner PYs in a regiment in order to get 50 more proper maintainers. I can always replace the gunner PYs with reservists - you can't do that as well with the techs.

If you want a war reserve then figure out what you need "in reserve" and acquire that. Just because the Ukrainians were able to put several dozens of different guns into action because of necessity doesn't mean we have to buy a 50-year-old gun. The base L118 goes back to the mid 70s. It's biggest drawback are limited terminal effects and range.

If we're looking for something for ARes gunners to do in the interim then start working on loitering munitions, STA systems (including UAVs and radars), EW/MI fusion links. The biggest challenge to the artillery right now, IMHO, is an efficient system of joint fires integration. Developing fast sensor to effector kill-chains. We need to mobilize a whole slew of sensor systems that will supplement the lonely FOOs with their currently limited views of the battlefield. Then we need new and effective decision and targeting systems that rapidly deploy the right effects on the target in minutes. We need offensive and defensive EW suites working in tandem with artillery - its part of JFM but its still in progress. - Oh and we need a ton of air defence.

The priority has been given to acquire these systems and we should be organizing and starting to develop the new doctrine - including organization and training - for them now. We really don't have the time to waste on guns we won't use. I'd rather take a a pickup truck and modify it to shoot 2.75 inch rockets in order to train people in the tactical deployment and engagement of HIMARS. The same with sending folks using ersatz UAVs and sending folks out with ersatz air defence systems. They can do that in the suburbs of Toronto and Montreal. We need to learn new stuff and not go back to 1950s level gun drill.

Sorry for the rant. I'm really not too happy with the lackadaisical speed with which our RegF is absorbing and adapting to the new reality of war. I sometimes get the feeling that if our military was running the Ukrainian forces and industry then they'd have lost the war a year or two ago.

$0.02

Rant Off.

 

[Colin Parkinson]

I don't have your confidence they can fix the system for the Reserves in our lifetime, sans all out war. So yea I take a bunch of new "crappy pop howitzers" with modern FCS to train and keep those reservists from walking out the door. If you make them only a drone unit, the CAF will eventually cut off the funding and they be flying a few drones held together with gun tape as there are no replacements, because the factory in Quebec went out of business. You can have the L119 AND your SHORAD/Drone/Locating equipment at the same armoury. Young gunners come in and learn the howitzer first, then can learn all the other skillsets depending on the equipment they get.

 

[Kirkhill]

I can think of one reason for using the M777 at the reserve level over the M119. Versatility.

The larger calibre allows for larger missiles to be launched.

That 155mm barrel could launch not only conventional "short range" shells but can also launch 150 km powered projectiles like NAMMO's ramjet projectiles. I don't see why, witb a low charge it couldn't also punt Loitering Munitions and UAVs into flight.

HIMARS is being adopted as both a tactical weapon and a strategic one.

The M777 could likewise be dual purposed. Short range in support of a Light Brigade or it could operate in the rear of a larger formation providing depth fires.

And it could possibly even serve as part of the air defence team.


M777 with an L52 barrel and HVPs (Hyper Velocity Projectiles) create a Multi Domain Artillery Cannon that could serve in the traditional role, as a 150 km ramjet launcher, potentially a UAV launcher, a Land Based Anti Ship system or an air defence / IAMD / counter-drone system.

US Army Initiates Development of 155mm Anti-Aircraft Artillery System

US Army Initiates Development of 155mm Anti-Aircraft Artillery System

www.armyrecognition.com

MDAC is based on a wheeled howitzer but does it hsve to be?

 

[FJAG]

I don't have your confidence they can fix the system for the Reserves in our lifetime, sans all out war.

I have absolute confidence that they can fix the reserve system starting tomorrow . . . if they put their mind to it.

I have zero confidence that they will fix the reserve system - ever.

I may be a dreamer, but I'm not a Pollyanna. If it hasn't been fixed in the sixty years that I've been involved in and been looking at it then the chances of a radical change are . . . well, pretty damn low. I don't think that even war will make a difference. They won't have time, and like before, they'll ad hoc their way through it. Remember that one of the the key elements of a viable reserve force is that not only does it have the trained people (which it doesn't have) but the equipment (which it doesn't have). Without that you stay an augmentation system on the minimal gear that you have.

When you look at Poland and Germany you can see the outline of a plan coming together. When you look at the UK and Canada then the absence of a plan is glaringly obvious.

 

[GR66]

I actually don't think we need them - we can continue to use clapped out C3s for saluting bases.

For operational artillery for an army of around 25,000 RegF and 30,000 ARes I see the following (which equates to two small expeditionary-capable armoured divisions, a larger homeland division and a general support division):

6 x SP regiments - 108 x 155mm SP guns plus 36 medium range UAV/LM launchers plus 6 x STA batteries
1 x light regiment - 18 - 24 x 155mm M777 plus 6 medium range UAV/LM launchers plus 1 x STA battery
6 x HIMARS regiments - 108 launchers plus 36 long range UAV/LM launchers plus 6 STA batteries
3 x STA regiments - 9 x STA/EW/MI fusion batteries plus 18 long range UAV/LM launchers
6 x AD regiments - 18 x mixed VSHORAD/SHORAD batteries
Plus an adequate number of training and tech spares.

Note that only two HIMARS regiments are allocated to the expeditionary armoured divisions. The other four are three: in the homeland division in an A2/AD role and one in the GS division that can go either way (my guess is homeland A2/AD and not expeditionary)

In total that needs about 10,000 gunners not counting sigs and MI or logisticians. We currently have just less than half of that in Reg and ARes gunners. If you want to arm Canada for a real war then you need to first provide the weapons that are needed. ARes forces will have to make a substantial contribution in all of these fields many of which do not need routine access to a firing range very often - maybe once per year - nor will they need full time soldiers during peacetime. Much of this works on simulation.

Eventually we'll have to think about an arty role in the field of several IAMD regiments.

I'd be happy to see this within the planned Maneuver Division/Defence of Canada Division structure.

Fires and AD are much more central to the defence of Canada than infantry and armour. Let the Maneuver Division fill out and sustain our existing Latvia Brigade contribution and let our additional support if war breaks out be Fires, AD and tons of logistical support rather than additional infantry and tank units. European NATO has enough population to outmatch Russia in terms of troop numbers but they are still possibly lacking in weight of precision fires, AD and overall magazine depth.

 

[FJAG]

I can think of one reason for using the M777 at the reserve level over the M119. Versatility.

The larger calibre allows for larger missiles projectile to be launched.

That 155mm barrel could launch not only conventional "short range" shells but can also launch 150 km powered projectiles like NAMMO's ramjet projectiles.

I don't see why, witb a low charge it couldn't also punt Loitering Munitions and UAVs into flight.

There are a lot of simpler systems to do that which would be part of a dedicated sensor to effector system. A round could be designed to do the job from a 155mm but it seems like overkill.

HIMARS is being adopted as both a tactical weapon and a strategic one.

Okaaayyyy.

The M777 could likewise be dual purposed. Short range in support of a Light Brigade or it could operate in the rear of a larger formation providing depth fires.

I wouldn't hold my breath for an L52 barrel for an M777 beyond the test models. There are already several functional truck mounted versions that fill the bill quite well. There isn't a big appetite - read enough sales - to make development costs worth while. It makes a fine airmobile gun - even airborne gun, as is, but that's a niche market.

And it could possibly even serve as part of the air defence team.

M777 with an L52 barrel and HVPs (Hyper Velocity Projectiles) create a Multi Domain Artillery Cannon that could serve in the traditional role, as a 150 km ramjet launcher, potentially a UAV launcher, a Land Based Anti Ship system or an air defence / IAMD / counter-drone system.

HVP makes a fine naval system where the gun is tied into a very sophisticated sensor and fire direction system that will rapidly and accurately deliver the round to the fast moving target.

I'm cautiously optimistic that something in the nature of an MDAC can be developed but it's not so much the gun and the projectile that is the key, it's the sensor systems and the automated gun-target orientation system and the terminal guidance systems that matter. The better the former, the easier the latter. On a ship gun-target orientation works well. In a field gun system it's a collection of systems rather than an integrated one. I'm pretty sure a technical solution can be found but it's a lot harder than on a ship and probably as dreadfully expensive as on a ship.

US Army Initiates Development of 155mm Anti-Aircraft Artillery System

US Army Initiates Development of 155mm Anti-Aircraft Artillery System

www.armyrecognition.com

MDAC is based on a wheeled howitzer but does it hsve to be?

I can see an MDAC - basically a fully automated turret on a chassis - have all the same systems making it a fully automated - load, track and slew and engage cycle - work at close to the same speed and accuracy as a naval gun (one still needs to couple it to sensors and automated fire direction systems). I don't see that on the M777 where all those functions are done by hand. One would need to seriously redesign the gun which would dramatically add to its weight and make it less versatile as a "light-weight" howitzer. The L52 barrel itself makes it a significantly heavier gun when you end up compensating for the heavier barrel and greater shock and stresses of long range firing.

 

[Kirkhill]

There are a lot of simpler systems to do that which would be part of a dedicated sensor to effector system. A round could be designed to do the job from a 155mm but it seems like overkill.

Okaaayyyy.

I wouldn't hold my breath for an L52 barrel for an M777 beyond the test models. There are already several functional truck mounted versions that fill the bill quite well. There isn't a big appetite - read enough sales - to make development costs worth while. It makes a fine airmobile gun - even airborne gun, as is, but that's a niche market.

HVP makes a fine naval system where the gun is tied into a very sophisticated sensor and fire direction system that will rapidly and accurately deliver the round to the fast moving target.

I'm cautiously optimistic that something in the nature of an MDAC can be developed but it's not so much the gun and the projectile that is the key, it's the sensor systems and the automated gun-target orientation system and the terminal guidance systems that matter. The better the former, the easier the latter. On a ship gun-target orientation works well. In a field gun system it's a collection of systems rather than an integrated one. I'm pretty sure a technical solution can be found but it's a lot harder than on a ship and probably as dreadfully expensive as on a ship.

I can see an MDAC - basically a fully automated turret on a chassis - have all the same systems making it a fully automated - load, track and slew and engage cycle - work at close to the same speed and accuracy as a naval gun (one still needs to couple it to sensors and automated fire direction systems). I don't see that on the M777 where all those functions are done by hand. One would need to seriously redesign the gun which would dramatically add to its weight and make it less versatile as a "light-weight" howitzer. The L52 barrel itself makes it a significantly heavier gun when you end up compensating for the heavier barrel and greater shock and stresses of long range firing.

Points taken on the complexity re the cannon-launched UAVs (although I think Excaliburs and Ramjets are crossing lines) and on the MDAC issue.

Which caused me to wonder this:

Is there merit to buying the RCH155 module as a stand-alone system?

Boxer RCH 155 demonstrates MRSI and fire-on-the-move capabilities – Below The Turret Ring

below-the-turret-ring.com

.....

In a reserve capacity the lack of a tractor would reduce the maintenance bill. Placing them on trailers for ground emplacement to move them to static defence positions would fulfill much of that MDAC - IAMD function - simply a larger calibre version of the Millenium/SkyRanger turrets.

 

[FJAG]

Is there merit to buying the RCH155 module as a stand-alone system?

I don't. But that's me. I think the need to relocate systems is always there, even for once located in relatively static areas such as FOBs. I don't think the FOB-based type of warfare is dead. It's gone to sleep for a while but if the unpleasantness with Russia ends it may wake up again. Maybe even for Pacific Islets controlling vital straights. Who knows.

In a reserve capacity the lack of a tractor would reduce the maintenance bill.

Don't tell me your going to ride the "reserves equals poor maintenance wave" as well. Poor maintenance is a product of understrength and under supported logistics. Fix the logistics and the reserves will be fine with complex equipment. Based on the latest equipment readiness figures for the Canadian land forces I'll lay even money that the US ARNG and USAR have a higher equipment readiness score than our RegF. But I digress.

Placing them on trailers for ground emplacement to move them to static defence positions would fulfill much of that MDAC - IAMD function - simply a larger calibre version of the Millenium/SkyRanger turrets.

Trailers are actually a solid idea for systems generally dedicated to point defence rather than mobile operations. To me, mobility means anything that doesn't require a crane to lift the thing onto a HET flatbed. A trailer with on-board power to drop stabilizers and wheels to operate in semi-rough terrain and capable of being towed by a standard army heavy transport vehicle rather than a specialist one would fit my bill.

 

[Kirkhill]

I don't. But that's me. I think the need to relocate systems is always there, even for once located in relatively static areas such as FOBs. I don't think the FOB-based type of warfare is dead. It's gone to sleep for a while but if the unpleasantness with Russia ends it may wake up again. Maybe even for Pacific Islets controlling vital straights. Who knows.

FOBS (Forward Operating Bases) are an expeditionary/manoeuvre construct.

PS - for clarification

When I used FOBS in the thread title I was referring to the Reagan Star Wars era Fractional Orbit Bombardment System which seems to be back on the table.

Don't tell me your going to ride the "reserves equals poor maintenance wave" as well. Poor maintenance is a product of understrength and under supported logistics. Fix the logistics and the reserves will be fine with complex equipment. Based on the latest equipment readiness figures for the Canadian land forces I'll lay even money that the US ARNG and USAR have a higher equipment readiness score than our RegF. But I digress.

I agree with you that an appropriate support system can be created that will work with the reserves. But is the money, manpower and effort necessary if the unit isn't going to be hieing itself hither and yon?

Are you differentiating between GBAD as an expedtionary asset and IAMD as a continental aset? Because I see IAMD as having a strong, if not dominant Ground Based component. I also see that as a natural fit for a locally based "garrison" artillery - one that is going to be quiet through most of its operational life buthas to be able to come out of hibernation in a hurry. Minutes not months.

Trailers are actually a solid idea for systems generally dedicated to point defence rather than mobile operations. To me, mobility means anything that doesn't require a crane to lift the thing onto a HET flatbed. A trailer with on-board power to drop stabilizers and wheels to operate in semi-rough terrain and capable of being towed by a standard army heavy transport vehicle rather than a specialist one would fit my bill.

We agree.

The defence of Kiev and Lviv, or Ottawa and Halifax have little to do with manoeuvre. Those people, their docks and runways, aren't going anywhere. They need to be defended in place. Hence palletised SkyRanger 35s and NASAMS. Patriots and Mk70 PDS seacans aren't exactly mobile so much as relocatable.

 

[Kirkhill]

There is something wrong with American industry

Hanwha Defense USA signs U.S. Army research deal on K9 howitzers and 58-calibre cannon programme

Hanwha Defense USA has secured a Cooperative Research and Development Agreement with the U.S. Army Combat Capabilities Development Command Armaments Center to study integration of a 58-calibre cannon into its K9 family of self-propelled howitzers.

defence-industry.eu

howizzit that other countries can create and constantly upgrade small batches of workable systems where America struggles?

 

[Czech_pivo]

There is something wrong with American industry

Hanwha Defense USA signs U.S. Army research deal on K9 howitzers and 58-calibre cannon programme

Hanwha Defense USA has secured a Cooperative Research and Development Agreement with the U.S. Army Combat Capabilities Development Command Armaments Center to study integration of a 58-calibre cannon into its K9 family of self-propelled howitzers.

defence-industry.eu

howizzit that other countries can create and constantly upgrade small batches of workable systems where America struggles?

Graft?
Greed?
A ‘one and done’ approach?

 

[FJAG]

Are you differentiating between GBAD as an expedtionary asset and IAMD as a continental aset? Because I see IAMD as having a strong, if not dominant Ground Based component.

In using current terminology, I'm being imprecise. By IAMD I mean what it says. By GBAD I'm referring to the current army's VSHORAD/SHORAD system for the manoeuvre brigade and not to ground based systems in the general sense. I agree. The main components of IAMD will be ground based.

There is something wrong with American industry

Hanwha Defense USA signs U.S. Army research deal on K9 howitzers and 58-calibre cannon programme

Hanwha Defense USA has secured a Cooperative Research and Development Agreement with the U.S. Army Combat Capabilities Development Command Armaments Center to study integration of a 58-calibre cannon into its K9 family of self-propelled howitzers.

defence-industry.eu

howizzit that other countries can create and constantly upgrade small batches of workable systems where America struggles?

In fairness the Americans do too. M1s, M2s, M109s, MLRS have all undergone product improvement programs. The scale with which the US has to work, and its concurrent cost, limits how much and how often you can do it.

 

[Kirkhill]

I want to revisit the notion of the M777 as an IAMD asset.

The US Air Force translated the Hyper Velocity Projectile from the Navy's rail gun project to the M109A6 Paladin and employed it to shoot down a Kratos BQM-167 Skeeter target drone (the forebear of the UTAP-22 Mako CCA) which emulated a Russian cruise missile.

Composite Engineering BQM-167 Skeeter - Wikipedia

en.wikipedia.org

This prompted the consideration of the 155mm HVP / Cannon combination as the basis of the Multi Domain Artillery Cannon for inclusion in the Integrated Air Missile Defence system. Early announcements suggested that the Archer system, with its self-loading cannon, was a lead contender for the task but the RCH-155 is also under consideration.

Apparently self-loading was considered as a pre-requisite. But is that due to rate of fire?

The M109A6 Paladin has a published rate of fire of 1 round per minute sustained but 4 rounds per minute for 3 minutes (1 round every 15 secs or 3 rounds in 30 secs)

The Archer's rate of fire is given as 75 rounds per hour (or 1 round every 48 seconds) but only has a 21 round magazine that would be exhausted in 10 to 15 minutes. Its maximum rate is 8 to 9 rounds per minute or 3 rounds in 15 seconds - twice the rate of the M109.

The RCH-155 has a comparable rate of fire to the Archer but a slightly larger magazine of 30 rounds.

....

Now to take another look at the M777, specifically the M777A2 with the digital fire control system.
I understand that the M777A2 uses the L39 cannon.
I also understand that the barrel length is not critical to the employment of the HVP but that adjustments to the design of all 155mm cannons would be necessary to manage the higher pressures associated with the HVP projectiles. Such adjustments are assumed to still allow the use of all legacy projectiles.

Keeping the L39 barrel would eliminate the mobility issues reportedly associated with the experimental L52 barrel that was offered to India.

The M777 rate of fire is given as 2 rounds per minute sustained or 4 rounds per minute rapid, similar to the M109A6 Paladin and likewise half that of the self-loaders.

So what happens if, rather than deploying 1 expensive Archer or RCH-155 with its crew of 2 we were to employ 2 cheap M777s with their crews of 10 (total of 20 trained gunners all working in sync.)?

I am going to assume that the DFCS could lay both guns on the same target effectively.

 

[FJAG]

Apparently self-loading was considered as a pre-requisite. But is that due to rate of fire?

The M109A6 Paladin has a published rate of fire of 1 round per minute sustained but 4 rounds per minute for 3 minutes (1 round every 15 secs or 3 rounds in 30 secs)

The first thing to remember is that on a ship, the round usually comes as a complete package with a fuze, projectile, cartridge with a fixed charge and a primer. On the 155 series of ammunition, the fuzed projectile is separate from the charge bags (or modular artillery charge system (MACS)) and a separate primer.

The M109 has one man in the turret who handles ammo and several outside that prepare components and get them into the gun. Assuming that no fuze needs setting the #4 hauls out a loading tray and rammer, places the 93 lb round on the tray, rams the round, stows the tray, loads the proper charges, closes the breach, inserts a primer into a lock, attaches a lanyard and pulls it when told to fire. Then gets the next round out of the rack or off the floor and so on.

Yes, I've seen four rounds per minute done but usually just for four or five rounds. We didn't have all that many to blow down range in a single fire mission.

I don't know the full routine inside either archer or RCH. They do use the same fuzes and they can be set by an induction fuze setter. The projectiles and MACS are still separate and loaded separately. Some systems uses a primer magazine (sufficient for the rounds on board, others work electrically or with a microwave system. I think Archer uses a magazine. AS-80 did. Not sure about RCH but PzH 2000 uses a 32 primer magazine.

The Archer's rate of fire is given as 75 rounds per hour (or 1 round every 48 seconds) but only has a 21 round magazine that would be exhausted in 10 to 15 minutes. Its maximum rate is 8 to 9 rounds per minute or 3 rounds in 15 seconds - twice the rate of the M109.

The RCH-155 has a comparable rate of fire to the Archer but a slightly larger magazine of 30 rounds.

Yup. I don't doubt that they're faster.

Now to take another look at the M777, specifically the M777A2 with the digital fire control system.

The digital fire control is a bit faster than manual but not too much. Usually the delay in relaying the gun comes from the recoil and rocking about as the tube tuns back into battery. Effectively the #3 watches a screen and turns handwheels until some bubbles on it are zero'd. The biggest saving for digital systems is that firing data can be digitally transferred from the firing data computer to the gun digitally. And in time from the sensor through the computer to the gun.

I understand that the M777A2 uses the L39 cannon.
I also understand that the barrel length is not critical to the employment of the HVP but that adjustments to the design of all 155mm cannons would be necessary to manage the higher pressures associated with the HVP projectiles. Such adjustments are assumed to still allow the use of all legacy projectiles.

I don't know the pressures involved, but the L52 and above guns have significantly stronger breeches and breech blocks because the longer range ammo adds some major stresses. My general knowledge of the HVP is basically that higher pressures are involved to get the "hyper" thing.

Keeping the L39 barrel would eliminate the mobility issues reportedly associated with the experimental L52 barrel that was offered to India.

The M777 rate of fire is given as 2 rounds per minute sustained or 4 rounds per minute rapid, similar to the M109A6 Paladin and likewise half that of the self-loaders.

Yeah. It's about the same but the ramming process on the M777 is slower. The M109 uses a hydraulic rammer while the M777 needs to be rammed manually by two men in order to properly seat the round.

So what happens if, rather than deploying 1 expensive Archer or RCH-155 with its crew of 2 we were to employ 2 cheap M777s with their crews of 10 (total of 20 trained gunners all working in sync.)?

No clue.

I am going to assume that the DFCS could lay both guns on the same target effectively.

There's a bit of an issue in that the systems right now are designed to work on a two-dimensional flat plane (bearing and range) with a special offset (angle of sight) that compensates for altitude difference between gun-target. It has limited application for a moving target in three dimensions. Not insurmountable - WW2 AA predictors produced solutions for slower kit and planes so I can't see why it can't be done. I see a lot of problems but won't gainsay it.

 

[Colin Parkinson]

Pushing a gun to shoot very long distances, when you have HIMAR seems to be a waste.