Tanks guns and ammunition.

[Ramlaen]

 

 

[Ramlaen]

 

[Belesarius]

A little low calibre for this thread, but I don't feel like starting a new one for medium calibre guns.

 

http://www.janes.com/article/75087/orbital-atk-progresses-new-medium-calibre-munition-development

 

Looks kinda neat. Would like to know more about the 'command guided' 30mm type for sure.

 

[Ramlaen]

1 hour ago, Belesarius said:

A little low calibre for this thread, but I don't feel like starting a new one for medium calibre guns.

 

http://www.janes.com/article/75087/orbital-atk-progresses-new-medium-calibre-munition-development

 

Looks kinda neat. Would like to know more about the 'command guided' 30mm type for sure.

 

 

It sounds like they are scaling down the 50mm EAPS guidance system.

[Ramlaen]

 

 

[Bronezhilet]

14 hours ago, Ramlaen said:

 

 

Those are mach waves, mister Grant Turnbull.

[Ramlaen]

A quick comparison of the DM11, M339 Hatzav and XM1147 that I slapped together, since they are all programmable 120mm HE rounds that use tungsten pellets.

 

[Ramlaen]

Rarefaction Wave Gun, the bastard child of  traditional large caliber guns and recoilless rifles.

[Ramlaen]

Something I came across while looking for something completely different, a patent on kinetic energy projectiles that lengthen after being fired.

 

[FORMATOSE]

Does anyone has this publication ?

 

Richard P. Davitt, "Design and Development of the XM578 APFSDS-T Cartridge for the 152mm XM150 Gun/Launcher: XM803 Main Battle Tank Program (U) ," Picatinny Arsenal Technical Report 4778, December 1975.

[Collimatrix]

On 11/6/2017 at 2:20 PM, Ramlaen said:

Rarefaction Wave Gun, the bastard child of  traditional large caliber guns and recoilless rifles.

I did a thread on these some time ago.

 

On 11/14/2017 at 10:08 PM, Ramlaen said:

Something I came across while looking for something completely different, a patent on kinetic energy projectiles that lengthen after being fired.

 

 

  Reveal hidden contents

 

 

 

 

 

 

Extended rods are mentioned in this overview of novel penetrator technologies.

[Ramlaen]

45 minutes ago, Collimatrix said:

I did a thread on these some time ago.

 

 

The links are dead but searching Kathe on DTIC produces a lot of relevant results.

[Alzoc]

Wanted the opinion of the forum about guided ammunition for MBTs

 

http://preprod.nexter-group.fr/images/stories/filiales/MUN/char/40055_POLYNEGE_VF.pdf

 

In this case it's a French technology demonstrator (early 2000 I don't have an exact date), but IRC the US have a similar round in development (Plus the M982 Excalibur round that is already in service for artillery).

 

The advantage I see:

 

-Perform the same job than a top attack ATGM while being most likely cheaper (The flight control, electronics and warheads are by all mean the same but it doesn't need a booster)

-Added versatility for MBT (Just send the data from the BMS to the FCS, load the round and fire)

-Slightly faster than an ATGM (600-700 m/s vs 150-300 m/s for an ATGM), so maybe some APS might have a harder time intercepting it (not sure about that though)

 

Cons would be:

 

-The diameter or the warhead is limited by the gun (but the same apply for gun launched ATGM)

-Contrary to an ATGM those rounds have to follow a ballistic arc so in some terrain configuration they might not be able to hit the target.

 

Personnaly I think that the added range and versatility for MBTs is worth it (8km ; fire and forget ; NLOS capability could be a big deal if you have no artillery support available), but perhaps others will see it as a gadget.

[Ramlaen]

If we are talking active guidance and not INS/GPS my opinion is that

 

-I am really disappointed the XM1111 MRM got cancelled in a rash of short sighted cost cutting.

-Guided rounds fall into the special purpose niche that gun launched ATGMs do.

-Programmable airburst rounds (both the HE and KE variety) seem to have superseded guided rounds due to cost effectiveness.

-NLOS is an attractive potential.

 

 

[Collimatrix]

On 11/28/2017 at 2:59 AM, Alzoc said:

Wanted the opinion of the forum about guided ammunition for MBTs

 

http://preprod.nexter-group.fr/images/stories/filiales/MUN/char/40055_POLYNEGE_VF.pdf

 

In this case it's a French technology demonstrator (early 2000 I don't have an exact date), but IRC the US have a similar round in development (Plus the M982 Excalibur round that is already in service for artillery).

 

The advantage I see:

 

-Perform the same job than a top attack ATGM while being most likely cheaper (The flight control, electronics and warheads are by all mean the same but it doesn't need a booster)

-Added versatility for MBT (Just send the data from the BMS to the FCS, load the round and fire)

-Slightly faster than an ATGM (600-700 m/s vs 150-300 m/s for an ATGM), so maybe some APS might have a harder time intercepting it (not sure about that though)

 

Cons would be:

 

-The diameter or the warhead is limited by the gun (but the same apply for gun launched ATGM)

-Contrary to an ATGM those rounds have to follow a ballistic arc so in some terrain configuration they might not be able to hit the target.

 

Personnaly I think that the added range and versatility for MBTs is worth it (8km ; fire and forget ; NLOS capability could be a big deal if you have no artillery support available), but perhaps others will see it as a gadget.

 

 

I have been thinking about this a bit.  Here are my thoughts:

For the NATO 120mm, GLATGMs of any sort don't seem to make much sense if they use pure rocket propulsion.  They are very space inefficient because the 120mm cartridge case is strongly bottlenecked:

 

All of the volume inside the ammunition rack occupying the difference between the case diameter and the gun caliber is wasted when using GLATGMs.  This isn't so bad with the 125mm and 105mm guns, because they are not as strongly bottlenecked as the 120mm.  Really, the 120mm NATO smoothbore was designed to do one thing and do it really well, and that is fire the meanest APFSDS rounds on the battlefield so it can kill Soviet frying pan tanks dead.  It's a bit less efficient at everything else, but killing Ivan's endless sea of tanks was understandably prioritized.

 

Wasting volume is an important consideration because volume costs mass.  Every cubic centimeter inside a tank has to be protected by some amount of armor, and armor costs weight.  So wasting any of that space is an inefficiency that adds up surprisingly quickly.

So this gun-launched guided projectile is an improvement over GLATGMs, efficiency-wise because none of the volume of the projectile is wasted by being a rocket motor.  The projectile can, in principle, extend from the maximum overall length of the projectile to nearly the rear inside wall of the case head like M829A3 with all the necessary propellant packed around it.  The only problem is that all the electronics and fin actuators and whatnot in the guided projectile need to be hardened to withstand acceleration inside the gun tube, which is quite a bit higher than the gentler acceleration of a rocket motor.

 

But that still leaves the question of why you would want this in the ammo rack instead of another round of HEAT-MP or APFSDS.  In my opinion, indirect fires are best left to dedicated artillery.  And if the MBTs are out on the prowl without artillery or air support, someone has some explaining to do.

 

The place where I see this sort of round being very useful is on one of those light-medium "expeditionary tanks" that are periodically popular, or even on something like a Centauro.  Those sorts of vehicles are supposed to be light enough that they can be easily deployed internationally to sudden crises in lighter transport aircraft than proper MBTs require.  In that sort of situation, it seems a lot more likely that the expeditionary force won't have proper artillery support, since SPGs have become just as big and almost as heavy as MBTs and will likely be left at home.

[Alzoc]

55 minutes ago, Collimatrix said:

snip

 So if I rephrase it:

 

-Better volume efficiency than GLATGM

-Not really useful for an MBT if the combined arms doctrine is carried out properly, plus it decrease the amount of general purpose rounds carried

-Could be useful for AFV acting as a rapid response force or long range recon

 

That raise the question of what will the future expeditionary vehicle look like.

 

Personally I don't think that MBT caliber guns are the way to go (105 - 120 mm) and think that a tandem of 40-30 mm AC plus ATGM is more flexible.

And in the later configuration, ATGM are often strapped externally so you can have a bigger warhead. Granted the volume efficiency problem remain, but it is less prominent since AC round takes less space.

Still it could be a useful concept for existing gun fire support vehicles (MGS, Centauro and all the others)

 

Also truck based SPG can be quite easily used for expeditionary purpose and they pack just as much firepower as tracked SPG.

The French deployment in Mali (Operation Serval) is a testament to that since we were able to quickly airlift 4 Caesar which then chased the enemy in a battlefield roughly the size of metropolitan France.

For more details there is a report from RAND:

 

https://www.rand.org/content/dam/rand/pubs/research_reports/RR700/RR770/RAND_RR770.pdf

 

In my eyes the added bonus having those rounds in MBT is that they are generally closer to the lines which mean a shorter reaction time, if a friendly need support:

 

Direct fire support > Mortar > Artillery > Air support (reaction time wise)

 

So with a multi-purpose warhead those rounds could allow MBT to take the same role than self-propelled mortars with the added bonus of being more resilient to enemy fire (since SPM are often APC based) which would free the later for another front or simply increase the volume of fire.

However saturation and area attack cannot be used with those kind of round (since an MBT can only embark a limited number of said rounds), so they are limited to punctual and high value targets.

[Collimatrix]

13 minutes ago, Alzoc said:

 So if I rephrase it:

 

-Better volume efficiency than GLATGM

-Not really useful for an MBT if the combined arms doctrine is carried out properly, plus it decrease the amount of general purpose rounds carried

-Could be useful for AFV acting as a rapid response force or long range recon

 

That raise the question of what will the future expeditionary vehicle will look like.

 

Personally I don't think that MBT caliber guns are the way to go (105 - 120 mm) and think that a tandem 40-30 mm AC plus ATGM is more flexible.

And in the later configuration, ATGM are often strapped externally so you can have a bigger warhead. Granted the volume efficiency problem remain, but it is less prominent since AC round takes less space.

So it could be a useful concept for existing gun fire support vehicles (MGS, Centauro and all the others)

 

In my eyes the added bonus having those rounds in MBT is that they are generally closer to the lines which mean a shorter reaction time, if a friendly need support:

 

Direct fire support > Mortar > Artillery > Air support (reaction time wise)

 

So with a multi-purpose warhead those rounds could allow MBT to take the same role than self-propelled mortars with the added bonus of being more resilient to enemy fire (since SPM are often APC based) which would free the later for another front or simply increase the volume of fire.

However saturation and area attack cannot be used with those kind of round (since an MBT can only embark a limited number of said rounds), so they are limited to punctual and high value targets.

 

 

That is an accurate paraphrase, yes.

There is some merit to the AC+ATGM configuration for a light tank.  I am not quite sure what you mean by a "tandem AC," though.  AC+ATGM certainly allows a lot more flexibility in vehicle design, and in particular it allows the turret to be a lot smaller since it doesn't need to handle the enormous gun breech.  IMO, ATGMs from such a vehicle should be fired vertically and then thrust vector towards the target.  Swingfire ATGM had this capability (or close to it) decades ago, and electronics have only gotten better and cheaper since then.  Also, I think there's a case to be made for having this sort of vertically-launched ATGM be a general-issue weapon, not just a specialized item for light tanks.  That would mean that an ATGM crew could get away with exposing only the spotter and guidance module (if SACLOS or beam-riding) while the ATGM tube is hidden behind cover.

 

MBT caliber guns are attractive for anything that's expected to fight MBTs.  It's a lot harder to counter APFSDS than it is to counter ATGMs.  Also, gun ammunition is usually smaller for the same ballistic capability than missiles until very extreme velocities.  Using a gun barrel simply as a tube to fling a rocket out of seems silly, however, unless it's a rocket-assisted, gun-fired projectile, which has some interesting potential efficiency advantages for kinetic energy penetrators.  Gun ammunition will tend to be lighter or smaller for a given number of shots than rockets as a general rule though, and I think that can't be overlooked for expeditionary units, which may be in a precarious logistical situation.  Gun ammunition will tend to be cheaper as well, but I don't think that's an enormous consideration for many expeditionary force scenarios.  Presumably expeditionary forces are being rushed to the scene of an international political disaster in small numbers because getting a force to the scene quickly is the overriding consideration.  If their ammo is expensive, it's not a big deal.

[Alzoc]

2 hours ago, Collimatrix said:

I am not quite sure what you mean by a "tandem AC," though.

I just meant a tandem of an AC in combination with an ATGM, not a twin AC or something like that.

May have phrased that one poorly.

2 hours ago, Collimatrix said:

MBT caliber guns are attractive for anything that's expected to fight MBTs.  It's a lot harder to counter APFSDS than it is to counter ATGMs.  Also, gun ammunition is usually smaller for the same ballistic capability than missiles until very extreme velocities.  Using a gun barrel simply as a tube to fling a rocket out of seems silly, however, unless it's a rocket-assisted, gun-fired projectile, which has some interesting potential efficiency advantages for kinetic energy penetrators.  Gun ammunition will tend to be lighter or smaller for a given number of shots than rockets as a general rule though, and I think that can't be overlooked for expeditionary units, which may be in a precarious logistical situation.  Gun ammunition will tend to be cheaper as well, but I don't think that's an enormous consideration for many expeditionary force scenarios.  Presumably expeditionary forces are being rushed to the scene of an international political disaster in small numbers because getting a force to the scene quickly is the overriding consideration.  If their ammo is expensive, it's not a big deal.

In general if you want to use a full pressure gun, you better use a tracked vehicle since it will save weight on the suspension, and the vehicle will also be smaller.

But at the same time a tracked vehicle will often exceed 20 metric ton anyway.

Tracks are more efficient weight-wise but they  automatically put the vehicle above a  minimal weight.

 

The M8 is an exception since it was designed to be just light enough to be squeezed inside a C-130, and I guess that some serious compromises were made for that.

 

Light tanks can potentially be airlifted by tactical aircrafts but have, generally, a greater logistical trail than wheeled vehicles (higher fuel consumption and no parts commonality with APC and IFVs deployed alongside them) which is also a problem for an expeditionary force. Also their effective range will be smaller.

 

A Centauro II will barely fit in an A400M and for the US army to airlift such a vehicle would require the use of a C-17 (which is not as flexible as a C-130 in term of possible landing zone).

The MGS will fit in a C-130 thanks to it's unmanned turret but it's nowhere near the capability of a Centauro II (and most likely of a B1 Centauro as well, especially in the AT department) but it's quite an old design anyway.

If it were to be remade nowadays, I think it would end up heavier and larger.

In the end I think that there is two school:

 

-The European one which use heavy (25-30 metric ton) IFV-based vehicles in combination with the A400M (which is a sort of heavy tactical aircraft). The vehicles may use either a gun (which is not the best idea for wheeled vehicles) or an AC+ATGM combo

-The US that use lighter and less protected wheeled vehicles (Stryker family) and if a bigger vehicle is needed will just use a C-17 and land it on a better airstrip.

 

In the end it mostly comes down to the US having access to a heavy lift strategical aircraft and having vastly superior logistics than European country, while the European will have access to a better tactical aircraft.

[Bronezhilet]

5 hours ago, Alzoc said:

I just meant a tandem of an AC in combination with an ATGM, not a twin AC or something like that.

May have phrased that one poorly.

In general if you want to use a full pressure gun, you better use a tracked vehicle since it will save weight on the suspension, and the vehicle will also be smaller.

But at the same time a tracked vehicle will often exceed 20 metric ton anyway.

Tracks are more efficient weight-wise but they  automatically put the vehicle above a  minimal weight.

 

The M8 is an exception since it was designed to be just light enough to be squeezed inside a C-130, and I guess that some serious compromises were made for that.

 

Light tanks can potentially be airlifted by tactical aircrafts but have, generally, a greater logistical trail than wheeled vehicles (higher fuel consumption and no parts commonality with APC and IFVs deployed alongside them) which is also a problem for an expeditionary force. Also their effective range will be smaller.

 

A Centauro II will barely fit in an A400M and for the US army to airlift such a vehicle would require the use of a C-17 (which is not as flexible as a C-130 in term of possible landing zone).

The MGS will fit in a C-130 thanks to it's unmanned turret but it's nowhere near the capability of a Centauro II (and most likely of a B1 Centauro as well, especially in the AT department) but it's quite an old design anyway.

If it were to be remade nowadays, I think it would end up heavier and larger.

In the end I think that there is two school:

 

-The European one which use heavy (25-30 metric ton) IFV-based vehicles in combination with the A400M (which is a sort of heavy tactical aircraft). The vehicles may use either a gun (which is not the best idea for wheeled vehicles) or an AC+ATGM combo

-The US that use lighter and less protected wheeled vehicles (Stryker family) and if a bigger vehicle is needed will just use a C-17 and land it on a better airstrip.

 

In the end it mostly comes down to the US having access to a heavy lift strategical aircraft and having vastly superior logistics than European country, while the European will have access to a better tactical aircraft.

This is what Colli means by "rocket-assisted, gun fired projectile" by the way: 

 

 

 

 

[Ramlaen]

Qualification testing of 30x173mm TPDS made by Orbital ATK, GD-OTS and NAMMO back in 2010/2011.

 

[Ramlaen]

Anyone want to weigh in on a claim that Svinets was only the R&D name and that the BM48 round is Svinets-1?

[SH_MM]

I have been searching for informations regarding current Chinese APFSDS ammo for a discussion in another forum... seems interesting.

 

 

The older APFSDS design had a windshield and a copy of the M829A2's "stepped tip" to maximize penetrator length. According to the original poster, the left APFSDS shown in this image has a WHA penetrator, the other one has a DU one and is therefore shorter (due to keeping a desired velocity I assume).

 

 

The Type II M APFSDS has a penetration of 220 mm at 66.4° at 2,000 metres or roughly 550 mm along the line-of-sight. It has a muzzle velocity of 1,700 m/s and is overall a bit lighter than the DTW-125. The PTZ98 II round for the 120 mm smoothbore gun has similar armor penetration, but a lower muzzle velocity of only 1,660 m/s... so it either has better flight characteristics or a longer penetrator (overall length of projectile is 655 mm, so penetrator length most likely is less than 600 mm). The 105 mm DTW2 APFSDS penetrates 150 mm at 71° at 2,000 m, which is roughly 460 mm along the line of sight.

125 mm BTJ1 HEAT penetrates 180 mm steel at 68° or roughly 480 mm unsloped steel, so performance seems somewhat poor.

 

 

125 mm Type IIM or 125 mm DTW-125 APFSDS in front, at the left side is an old 105 mm APFSDS not being sold anymore

 

Old 105 mm APFSDS has a penetration of 460 mm (220 mm at 61.4°) and a muzzle velocity of 1,530 m/s.

 

The 105 mm BTA2 APFSDS seems to be nearly identical to the DTW2, but has a much higher penetration 220 mm at 66.42° at 2,000 m. That's about 550 mm along the line of sight! Muzzle velocity is slightly better than on the DTW2 and old APFSDS (1,540 m/s instead of 1,530 m/s). The projectile is much longer (703 mm vs 636 mm), but the weight has slightly decreased from 6 kg to 5.9 kg for the projectile. Do the Chinese utilize composite sabots?

 

125 mm DTW-125 APFSDS on the top, unknown two other rounds.  Note that the 120 mm APFSDS seems to be a lot more beefy (longer road) than the previous PTZ89 II. The 105 mm APFSDS also has a "DTW" name, so it is probably the DTW2 above.

 

 

These two photos confirm that the upper APFSDS is indeed the DTW-125

 

 

 

The APFSDS round is called DTW-125 and supposedly capable of penetrating 220 mm steel at 68.5° slope and 2,000 m distance, which is roughly equal to 600 mm along the line of sight. The muzzle velocity is 1,740 m/s and the overall weight of the complete round (both parts) is 21.36 kilograms. Dispersion at 1,000 m is 0.25 x 0.25 m on average. Some claim that the DTW-125 and DTW10-125 APFSDS rounds can only be fired from the Type 99(A) tanks.

 

 

For the VT-4 the Chinese manufacturer NORINCO is offering the BTA4 APFSDS. I wonder if this is equivalent to the Type II M or the DTW-125...

The size comparison between BTA4 and BTJ1 HEAT suggests that the BTA4 APFSDS is identical in length to the Type II M. I personally would asusme that Type II M and DTW-125 were identical (seem to be similar sized), if it wasn't for the differences in armor penetration and velocity. So that points to a stronger powder charge or a composite sabot.

 

 

The latest round is the DTW10-125, which has a slightly longer penetrator than the previous DTW-125. Supposedly it has no ballistic cap, but the penetrator extends into the tip. I remember reading similar patents from the 1980s or 1990s suggesting this layout, doesn't seem to be cutting edge. No performance data, but claimed to be 650-700 mm.

 

 

 

[SH_MM]

The website of the Iranian military industrial complex has an interesting selection of some odd ammo...

 

105 mm APFSDS with 460 mm penetration against  a steel target. No range data, no velocity. But look at the shape of the sabot... that's just odd.

 

106 mm recoilless rifle ammo

 

My personal favorite: a 122 mm HEAT shell for howitzers. Seems to be a copy of the 125 mm HEAT shell adopted for the smaller calibre. 220 mm at 60° penetration.

 

Old Soviet 125 mm ammo. Note that the penetration for the 105 mm APFSDS would exceed that of the BM-42 Mango based on their way of writing just a number without range data...

[Militarysta]

Greate post about chineese 125mm.

 

ps. on what forum discusion? Another chineese tanks fanboys?

[Krieger22]

Chinese APFSDS diagram: I can read Chinese, and that sounds about right.

 

The top line translates to "This shell's (read DU penetrator) layout is basically identical to the tungsten alloy shell (illustration 64), except for *text is cut off*.

 

The right one is indeed the DU penetrator. The tungsten penetrator's description is obscured by the watermark.