Kurganets & Boomerang Discussions Thread #1

http://periscope2.ru/wp-content/uploads/2013/03/20130217-IDEX-2013-5885.jpg

Uh, what bustle?

TR1 wrote:http://periscope2.ru/wp-content/uploads/2013/03/20130217-IDEX-2013-5885.jpg

Uh, what bustle?

Just behind the guns, and between the missiles.

You think that little area holds almost 900 30mm rounds? No way.

http://www.armyrecognition.com/images/stories/east_europe/russia/light_armoured/bmpt-72/BMP-72_Termintaor-2_fire_tank_support_armoured_infantry_fighting_vehicle_Uralvagonzavod_Russia_Russian_defense_industry_details_001.jpg

TR1 wrote:You think that little area holds almost 900 30mm rounds? No way.

http://www.armyrecognition.com/images/stories/east_europe/russia/light_armoured/bmpt-72/BMP-72_Termintaor-2_fire_tank_support_armoured_infantry_fighting_vehicle_Uralvagonzavod_Russia_Russian_defense_industry_details_001.jpg

Look at this photo:
http://btvt.narod.ru/1/armor_world/bmpt99.jpg

Gun mantle and the hull aren't connected.

http://www.armyrecognition.com/AlloPass/sample/bmpt_armyrecognition_russia_008.JPG

Ammo feed could easily be accomadated through the structure the 30mm guns are connected to.

And like I said, just look at the size of the "bustle" and imagine 900 rounds in there...impossble!

TR1 wrote:http://www.armyrecognition.com/AlloPass/sample/bmpt_armyrecognition_russia_008.JPG

Ammo feed could easily be accomadated through the structure the 30mm guns are connected to.

And like I said, just look at the size of the "bustle" and imagine 900 rounds in there...impossble!

Well, to think better, I don't REALLY know, and could be wrong about that, actually   

But I think, they aren't connected. For example, one variant of bradley had turret bustle with 900 rounds, and it wasn't significantly different from BMPT's, size wise.

But to really know the truth, I think, some internal diagrams would be pretty useful  


Actually, my thoughts came from the impression, that there isn't really much space left in the turret. And also keep in mind that 2A42 gun is dual-feed, so ammunition would be very tightly spaced through these pylons, let's not forget that gun elevating mechanisms are needed too.

Also, I don't think 30 mm ammo takes very much space in the first place.
http://upload.wikimedia.org/wikipedia/commons/8/8d/Autocanon_2A42_on_the_Mi28N_heli.JPG
Each of those boxes holds 150 rounds, if I'm not mistaken. Multiply these by six, and you'll get 900.

TBH I think each gun has only 1 ammunition feed, so one leads to an AP drum, the other to HE...this was discussed on Otvaga, I will need to find it though.

That diagram I linked above shows significant space for ammo storage in the ring inside the hull, and what else would you even use that space for?

http://vif2ne.ru/nvk/forum/arhprint/2509650#00264B52

This discussion about BMPT-72 mentions the elevation angle of the guns is limited by the ammo feed mechanics, I think that implies it does go through the "joint".

TR1 wrote:TBH I think each gun has only 1 ammunition feed, so one leads to an AP drum, the other to HE...this was discussed on Otvaga, I will need to find it though.

That diagram I linked above shows significant space for ammo storage in the ring inside the hull, and what else would you even use that space for?

Actually, I would be pretty glad to find that out too   

But what's the point in two guns, then you can have one dual-fed gun? Isn't the whole "increased firepower" hype a sham then?
Also, look closer to the photo I provided. It appears, that one cannon is rotated 90 degrees    Unless it's just the muzzle brake, and not the whole gun?





"This discussion about BMPT-72 mentions the elevation angle of the guns is limited by the ammo feed mechanics, I think that implies it does go through the "joint"."

Yes, that's possible. But it could also be limited by the bustle as well.   

Maybe you should ask that "Zivo" fellow, he appears to know about tanks, and stuff.  

TR1 wrote:TBH I think each gun has only 1 ammunition feed, so one leads to an AP drum, the other to HE...this was discussed on Otvaga, I will need to find it though.

That diagram I linked above shows significant space for ammo storage in the ring inside the hull, and what else would you even use that space for?

http://vif2ne.ru/nvk/forum/arhprint/2509650#00264B52

This discussion about BMPT-72 mentions the elevation angle of the guns is limited by the ammo feed mechanics, I think that implies it does go through the "joint".

I remember reading that, there were some diagrams included.

Yes well there was lots of arguments on the forums over the whole point of two guns with such a feed system, I don't remember what conclusion they actually came to.

Honestly, it would not surprise me at all, two guns with dual feeds each sounds complicated, especially in such a cramped arrangement. Might work if the ammo is indeed like you think in the module top itself, but I just can't imagine 900 rounds fitting there. Plus, they would be vulnerable in such an exposed position, and I think they would want to avoid that. Who knows....

I think the muzzle break on your pic is merging in with the black from the rest of the tank, it does kinda look like its tilted. But the rear of the gun seems oriented normally.

Zivo wrote:

TR1 wrote:TBH I think each gun has only 1 ammunition feed, so one leads to an AP drum, the other to HE...this was discussed on Otvaga, I will need to find it though.

That diagram I linked above shows significant space for ammo storage in the ring inside the hull, and what else would you even use that space for?

http://vif2ne.ru/nvk/forum/arhprint/2509650#00264B52

This discussion about BMPT-72 mentions the elevation angle of the guns is limited by the ammo feed mechanics, I think that implies it does go through the "joint".

I remember reading that, there were some diagrams included.

Ah speak of the devil!

Yeah I am glad I am not making it up, but I think the consensus was the feed was seperate.

I also remember diagrams that showed the magazines in the "carousel" within the hull, but ofc I can't find it right now.

Found it:

http://otvaga2004.mybb.ru/viewtopic.php?id=709&p=32

Yep, single feed.

TR1 wrote:Found it:

http://otvaga2004.mybb.ru/viewtopic.php?id=709&p=32

Yep, single feed.

Well, probably, I was wrong. But still, seems kinda weird to have 2 guns, instead of 1 dual-fed.

And here is the ammo belt:

etaepsilonk wrote:

TR1 wrote:Found it:

http://otvaga2004.mybb.ru/viewtopic.php?id=709&p=32

Yep, single feed.

Well, probably, I was wrong. But still, seems kinda weird to have 2 guns, instead of 1 dual-fed.

Yes the BMPT is full of weird "solutions".

Anyways, in this image of the "Epoch" weapon system, in the back right you can see another one being built. IMO it looks like it might have a BMP-2 style magazine. So the question is, what's in the bustle? Rearward facing APS modules? Additional ATGMs?

TR1 wrote:

etaepsilonk wrote:

TR1 wrote:Found it:

http://otvaga2004.mybb.ru/viewtopic.php?id=709&p=32

Yep, single feed.

Well, probably, I was wrong. But still, seems kinda weird to have 2 guns, instead of 1 dual-fed.

Yes the BMPT is full of weird "solutions".

I see. Maybe those "weird" solutions are what discouraged the Russian army from buying those?


To Zivo:

This is, of course, a pure speculation, but maybe a radar set could be fitted there?
With all this thermal absorbent stuff being developed, TI could have a difficult time finding targets in modern battlefield.

Re. BMPT



Unfortunately I cannot remember the original source of this image. I *believe* it was from UVZ but I'm not 100% sure.


There was actually another BMPT prototype made back in 2000 which featured a single 30mm. As you can see, it was deemed to be inadequate for the BMPT roll and the twin 30's were pursued.

This is, of course, a pure speculation, but maybe a radar set could be fitted there?
With all this thermal absorbent stuff being developed, TI could have a difficult time finding targets in modern battlefield.

The targeting radars you see on some ground weapons are rather small and wouldn't require much room. It may be a possibility, but I'm not sure how much of a benefit you would get from it. Keep in mind that camouflage kits like Nakidka and Bramble also have significant RCS reduction properties in addition to IR masking.

One thing I'm curious about though is whether or not the APS radars could be used for forming a 360° radar picture around the vehicle to help ID possible targets.

GarryB wrote:

It wont be.

They rejected the Burlak model of the T-72 upgrade because it stored 31 rounds in the turret bustle... putting exposed ammo above a troop compartment is the opposite of what they are trying to do with these new families of vehicles.

I think if they just mount the turret on top of a reinforced hull roof then the 30mm rounds cooking off wont be much of a problem.  
Its not like the 30mm rounds have couple tens of kilograms of propellant in them and have cardboard casings, so in event of an ammo cookoff the bustle would prolly sparkle and crackle but no huge boom.

To Zivo:
I see. But it's really a bit odd why they chose 2 guns. Since firing both AP and HE at the same time would be pretty useless in most occasions, maybe there were some reliability issues with guns? I mean, ammo belts are pretty long, and with quite a few curves. It's perfectly possible, that jamming rates would be higher than usual.

About the radar. Yes, those thermal suites also have RCS reduction measures, but you forget that those actually depends A LOT on wavelength (just like stealth airdraft). So, for example, Nakidka suit would be a bit more visible in centimetric band, I guess. And even milimetric radars, depending on range, aperture, and power, could burn-through.
And in the Epoha module, I was more thinking about larger, than hand held radars. If antenna won't move horizontally, you can have pretty insane apertures. But given LOS limitations, that would probably be an overkill. Unless, the module is destined for recon vehicles   

But again, that's just the speculation.


About APS. Well, since the widest FOV for radars is 120 degrees, you can achieve all round coverage with minimum of 3 antennas.

However, on somewhat unrelated note, I see that currently most APS are radar controlled. So, wouldn't it be advantageous for future IFVs and TDs to carry jamming equipment (or radars with jamming feature)? I mean, Krizantema-S could probably do that even now with it's radar, couldn't it?   



To collegeboy:

Actually, I was thinking the same myself. Given, that crew survivability is a big priority for BMPT, it made sense for me to think, that no ammo is stored internally. Well, but it's UVZ's product, not ours, after all  

For real? Shocked In case you don't know, BMPT has its ammo stored in the bustle as well.

The only ammo stored externally on the BMPT is the 4 Ataka missiles.

But I think, they aren't connected. For example, one variant of bradley had turret bustle with 900 rounds, and it wasn't significantly different from BMPT's, size wise.

Two things there... First the Bradley uses 25mm cannon shells which are rather smaller than the 30mm cannon shells the BMPT uses. Second the version of the Bradley that carries 900 25mm rounds uses the troop compartment for the extra ammo and carries 50% more ammo of everything the standard Bradley carries.

But what's the point in two guns, then you can have one dual-fed gun? Isn't the whole "increased firepower" hype a sham then?

The guns have dual feed so the gunner can select different ammo types for different targets. Having two guns gives the potential for double the rate of fire for fast aerial targets or to land more shells in any fixed period of time.

Yes, that's possible. But it could also be limited by the bustle as well.

Why mount the ammo externally if it does not move with the gun?

Yep, single feed.

I remember talking to a chap that claimed it could only fire one cannon at a time and thinking that was pretty dumb.

If the guns can't be elevated independently and one gun fires APFSDS rounds and the other fires HEI rounds then there would be no point in firing both guns at once because they would have totally different trajectories with the high velocity AP ammo going high and the lower velocity HE ammo going low.

Means I like the vehicle even less and the armata BMPT more...   

I think if they just mount the turret on top of a reinforced hull roof then the 30mm rounds cooking off wont be much of a problem. unshaven
Its not like the 30mm rounds have couple tens of kilograms of propellant in them and have cardboard casings, so in event of an ammo cookoff the bustle would prolly sparkle and crackle but no huge boom.

Bustles were not just rejected because of the threat of their exploding to the crew... in a BMPT there is no crew in the rear of the vehicle so a bustle would be safer than in the crew compartment.

They were rejected because they could be easily targeted by light enemy weapons to render the vehicle largely unarmed.

GarryB wrote:

Bustles were not just rejected because of the threat of their exploding to the crew... in a BMPT there is no crew in the rear of the vehicle so a bustle would be safer than in the crew compartment.

They were rejected because they could be easily targeted by light enemy weapons to render the vehicle largely unarmed.

got it, tho as i said 30 mm rounds would be hard to cook-off with their metal casings and low ammt of propellant. they could also copy the burlak magazine concept and have several 30mm magazines that could detach from the bustle when hit.

About the radar. Yes, those thermal suites also have RCS reduction measures, but you forget that those actually depends A LOT on wavelength (just like stealth airdraft). So, for example, Nakidka suit would be a bit more visible in centimetric band, I guess. And even milimetric radars, depending on range, aperture, and power, could burn-through.

Since we know very few details about Nakidka, it's a challenge to draw any accurate conclusions about it. From what I've read and seen, NII Stali has stated that they achieved something like a 1/5 reduction for X and L band radars. Capabilities against MMW radars is still a big question mark right now and frankly, I wouldn't touch it with a 10 foot pole.

Anyways, IMO it wouldn't be smart to have radars on ground vehicles that wouldn't absolutely need them. Radars are usually large targets, they have very little protection against small arms fire, and they're expensive to replace.


I wouldn't worry too much about the 30mm shells being dangerous to the crew. The BMP-2's in Syria have been preforming well and even after multiple RPG hits have failed to detonate.

The BMPT Terminator isn't perfect, but it's better than all other tanks out there for fighting an asymmetric war in urban environments. The Russians have also shown significant improvements to the BMPT concept since the first prototype rolled out almost two decades ago. The Russian MoD hasn't pushed for acquisition of the twin 30mm layout yet and if they choose KBTM's BMPT design for the Armata BMPT, most of this discussion will be irrelevant.

NII Stali has stated that they achieved something like a 1/5 reduction for X and L band radars. Capabilities against MMW radars is still a big question mark right now and frankly, I wouldn't touch it with a 10 foot pole.

I rather suspect the radar transparancy is optimised for higher frequencies, and keep in mind that radar protection does not require the vehicle becomes invisible... it just needs to break up the radar return to look like several different objects that are too small to be a vehicle... ie a rock, or indeed a civilian car.

MMW radar is AFAIK in the Ka and Ku bands.

BTW like I said the threat of 30mm cannon rounds cooking off was never the concern... it was 125mm propellent stubs exploding with regard to the Burlak, but in the case of IFVs a criticism leveled at the Ukrainian BTR-4 was that its ammo is external and therefore vulnerable even to large calibre sniper fire. The same criticism was leveled at the external RWS of the Lynx.

I doubt they would consider such an arrangement for the BMPT.

GarryB wrote:

BTW like I said the threat of 30mm cannon rounds cooking off was never the concern... it was 125mm propellent stubs exploding with regard to the Burlak, but in the case of IFVs a criticism leveled at the Ukrainian BTR-4 was that its ammo is external and therefore vulnerable even to large calibre sniper fire. The same criticism was leveled at the external RWS of the Lynx.

I doubt they would consider such an arrangement for the BMPT.

for BMPT yes, 120 mm gun/mortar + gsh-6-23 combo ftw  . whit this thing, well jsut have to wait and see.