Calibre of the IFV gun

Chrom

New Member
According to this,

http://www.fas.org/man/dod-101/sys/land/row/bmp-3.htm

The turret front armor of a BMP-3 is 30-35mm of RHAe. So it's questionable if it can even stop old Russian 30mm rounds. So if BMP-3s are all we're worried about, then the US (and other nations) can stick with 25mm/30mm.

OTOH, other countries who are planning on fighting a modern western military might want to consider improvements here. But, IMHO, they should focus far more on other areas like air defenses, modern C4ISR and asymmetric responses than the caliber of their IFV's autocannons. If they already have BMP-2s, then upgrade their sights, FCS, and armor and buy modern 30mm APFSDS rounds and ATGMs for them.

Here's a sample BMP-2 upgrade program,

http://www.kurganmash.ru/en/machines/bmp2u/
On the very same site (fas.org) its written - "Applique Armor (mm) Yes on turret ". Its in addiditional to normal armor. Moreoever, currently offered models differs from initial model. If NIIStali claims protection from 30mm AP round - than i have very little doubt what it can provide it, at least against most common 30mm rounds used in the West. Add to that possible heavy ERA package, and i wouldnt want to be on the guy's place trying to engage BMP-3 with 30mm.
 

B.Smitty

Defense Professional
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On the very same site (fas.org) its written - "Applique Armor (mm) Yes on turret ". Its in addiditional to normal armor. Moreoever, currently offered models differs from initial model. If NIIStali claims protection from 30mm AP round - than i have very little doubt what it can provide it, at least against most common 30mm rounds used in the West. Add to that possible heavy ERA package, and i wouldnt want to be on the guy's place trying to engage BMP-3 with 30mm.
If you go by the figures posted earlier, Russian 30mm AP has only around half the penetration performance of a modern, Western, tungsten 30mm APFSDS. There's no guarantee that even with applique, a BMP-3 would resist one of these new rounds. A modern DU round would do even better.

Plus, how many BMP-3s have been sold worldwide? ~600? Doesn't seem like there's a huge demand. If there eventually is a wide proliferation of BMP-3+ IFVs, then nations using the 30mm Bushmaster II can opt to upgrade to 40mm SuperShot and get near 35mm performance. Or just count on increasing performance of new 30mm sabot rounds.

For now, most threat nations are still driving around in BMP-1/2s and old BTRs, if they have anything.
 

Waylander

Defense Professional
Verified Defense Pro
We had the chance to test BMP-1/2 against Marder after our reunification.

If I remember correctly the test was done at 1.000m.
The 20mm of the Marder penetrated the BMP-2 all over the frontal area with every hit while the BMP-2 had problems with the turret and hull with the only shot penetrating the turret hit the optic (Always a weak point and I think the most problematic design issue).
And just one hull hit at the frontal right upper half of the hull penetrated the hull but without any countable damage to the interior.
Just some kevlar inlets would have dropped the damage to total zero.

I cannot believe that the BMP-3 is that the armor is so much better and can withstand a modern 30mm round while only being 200kg heavier (Without ERA) than his predecessor which was not able to withstand a 20mm non-DU round.

I have much respect for russian engineering but this would be a much too big lightjump in my eyes.
 

eckherl

The Bunker Group
Verified Defense Pro
We had the chance to test BMP-1/2 against Marder after our reunification.

If I remember correctly the test was done at 1.000m.
The 20mm of the Marder penetrated the BMP-2 all over the frontal area with every hit while the BMP-2 had problems with the turret and hull with the only shot penetrating the turret hit the optic (Always a weak point and I think the most problematic design issue).
And just one hull hit at the frontal right upper half of the hull penetrated the hull but without any countable damage to the interior.
Just some kevlar inlets would have dropped the damage to total zero.

I cannot believe that the BMP-3 is that the armor is so much better and can withstand a modern 30mm round while only being 200kg heavier (Without ERA) than his predecessor which was not able to withstand a 20mm non-DU round.

I have much respect for russian engineering but this would be a much too big lightjump in my eyes.
On certain areas on the flanks of a BMP 1 you can penetrate it with a 50 cal API round.
 

Chrom

New Member
If you go by the figures posted earlier, Russian 30mm AP has only around half the penetration performance of a modern, Western, tungsten 30mm APFSDS. There's no guarantee that even with applique, a BMP-3 would resist one of these new rounds. A modern DU round would do even better.

Plus, how many BMP-3s have been sold worldwide? ~600? Doesn't seem like there's a huge demand. If there eventually is a wide proliferation of BMP-3+ IFVs, then nations using the 30mm Bushmaster II can opt to upgrade to 40mm SuperShot and get near 35mm performance. Or just count on increasing performance of new 30mm sabot rounds.

For now, most threat nations are still driving around in BMP-1/2s and old BTRs, if they have anything.
Of course, there is no guarantee. But this applies both ways. Thats why an everage Joe would very much like a weapon with GUARATEED penetration.
As for BMP-3 numbers... the procuring & development of armored vehicles after the Cold War is pretty much sleeping, most major countries buy almost no new tanks, IFV's, etc - mostly they only upgrade old ones. Remember, we a speaking here about weapon for modern AFV which should remain viable for some time. As example, you wouldnt recommend 105mm MG for a new tank based on assumtion what "most tanks in the worlds are either T-72 or M-60 clones which as easely penetrated by modern 105mm round". While it might be true, still noone in they right mind would accept that argument.
 

Chrom

New Member
I cannot believe that the BMP-3 is that the armor is so much better and can withstand a modern 30mm round while only being 200kg heavier (Without ERA) than his predecessor which was not able to withstand a 20mm non-DU round.

I have much respect for russian engineering but this would be a much too big lightjump in my eyes.
T-64 weight about as much as T-55 - yet having twice the protection and much bigger gun. Good example. M1A2 weights only slightly more than M-60, its having MUCH better armor with bigger cannon. Another good example. Note, they share the same generation difference as BMP-2 and BMP-3.
 

Waylander

Defense Professional
Verified Defense Pro
What generation would a Puma be for you? ;)

And I state again that a BMP-3 (18,7 tons) weights just 200kg more than a BMP-2 which is penetrated by a 20mm all over the front and even 12.5mm on the sides.

Than we have a modern IFV like the Puma with 43tons (And I agree a bigger chassis) which claims to be able to withstand modern 30mm of which just the add-on armor weights round about 2/3 of the BMP-3s overall weight.

There is just no way a BMP-3 reaches this level of protection.

BTW, the "small" difference between a M60 and a Abrams is nearly 20 tons.

But I totally agree with you that if you want to be able to plan for the future a 35mm-40mm gun is better.
Not just because of possible armor of new IFVs but also when it comes to payload for HE and ABM ammo.
 

Chrom

New Member
What generation would a Puma be for you? ;)

And I state again that a BMP-3 (18,7 tons) weights just 200kg more than a BMP-2 which is penetrated by a 20mm all over the front and even 12.5mm on the sides.

Than we have a modern IFV like the Puma with 43tons (And I agree a bigger chassis) which claims to be able to withstand modern 30mm of which just the add-on armor weights round about 2/3 of the BMP-3s overall weight.

There is just no way a BMP-3 reaches this level of protection.

BTW, the "small" difference between a M60 and a Abrams is nearly 20 tons.

But I totally agree with you that if you want to be able to plan for the future a 35mm-40mm gun is better.
Not just because of possible armor of new IFVs but also when it comes to payload for HE and ABM ammo.
Puma is half-generation above the original BMP-3 and about some generation as upgraded BMP-3. I already said why comparing BMP-3 weight to BMP-2 cant lead to any conclusion - they are different generations. Comparing Puma weight to BMP-3 also is quite pointless as armor composition on both vehicles is vastly different. You may conclude however what Puma is most likely better protected than BMP-3 - but WHERE is this "better" and how much "better" would be completely unknown. If you have good information about frontal armor protection of BMP-3 - share it with us. I think armor material with exact layout would suffice to estimate RHA protection +- 25%. Last i heard basic armor was something like 35mm of equivalent steel inclined to cant-remember-yet degree.
P.S. You didnt answered my question - is Puma ALL-AROUND protected from 30mm? See, protecting only frontal area does not require such big weight as MBT.
 

swerve

Super Moderator
...
P.S. You didnt answered my question - is Puma ALL-AROUND protected from 30mm? See, protecting only frontal area does not require such big weight as MBT.
Why don't you look for the answer yourself? It's on the manufacturers website, in both German & English: protection level with basic & additional armour, front, sides, top . . .
 

swerve

Super Moderator
.... M1A2 weights only slightly more than M-60, its having MUCH better armor with bigger cannon. ....
Slightly? According to the GDLS website M1A2 weighs 69.54 US tons, i.e. 63.1 real tons. An M60A3 was 52.0 tons (57.3 US).
 

lobbie111

New Member
Although this is off topic for that I apologise but as Aussies we might hope to get the Puma but its very unikely, it seems like the perfect combat vehicle except the Airforce only has globemasters that can transport it. So in theory it has lost its main advantage of getting there quickly and stabilising the region.

But on the topic of gun calibre's, defence officials and designers have been debating it for years what calibre guns to put on their vehicles. Nowdays there is a trend for a low to medium calibre such as 20-40mm with a light 50. cal to 7.62mm co-axial armarment and a few complementary ATGM's. Rather than the older style of 50-105mm guns that are light tanks not IMV's.

*If I am wrong in anyway please correct me
 

rjmaz1

New Member
Protection comes at a huge cost in weight, fuel effeciency and mobility.

I believe if you get have the can see and shoot the enemy first then it doesn't matter if your armour can withstand 100mm or 20mm bullets.

In the gulf war, if you mounted the M1's gun and sight on a small 10 tonne vehicle it would have still slaughtered the Iraqi main battle tanks.

Thats why i think putting a big gun and sights on a lightweight vehicles can have many advantages.
 

Chrom

New Member
But on the topic of gun calibre's, defence officials and designers have been debating it for years what calibre guns to put on their vehicles. Nowdays there is a trend for a low to medium calibre such as 20-40mm with a light 50. cal to 7.62mm co-axial armarment and a few complementary ATGM's. Rather than the older style of 50-105mm guns that are light tanks not IMV's.

*If I am wrong in anyway please correct me
There are 2 trends: One is moving to 30-45mm gun + few ATGM's. Another is putting 100-120mm low velocity gun/mortar + 12.7/30mm/7.62 and ATGM's.
 

B.Smitty

Defense Professional
Verified Defense Pro
Of course, there is no guarantee. But this applies both ways. Thats why an everage Joe would very much like a weapon with GUARATEED penetration.
As for BMP-3 numbers... the procuring & development of armored vehicles after the Cold War is pretty much sleeping, most major countries buy almost no new tanks, IFV's, etc - mostly they only upgrade old ones. Remember, we a speaking here about weapon for modern AFV which should remain viable for some time. As example, you wouldnt recommend 105mm MG for a new tank based on assumtion what "most tanks in the worlds are either T-72 or M-60 clones which as easely penetrated by modern 105mm round". While it might be true, still noone in they right mind would accept that argument.
30mm Bushmaster gives you a weapon that can kill any enemy IFV we (the US) are likely to encounter in the near future.

Improved munitions can stretch this further.

There is a built-in, inexpensive growth path to 40mm SuperShot.

Going to a larger round reduces the number of stowed kills and can complicate internal feed arrangements.

25/30mm is good enough for the foreseeable future.

Larger weapons on western IFVs just aren't necessary, given the likely threats.
 

Waylander

Defense Professional
Verified Defense Pro
Protection comes at a huge cost in weight, fuel effeciency and mobility.

I believe if you get have the can see and shoot the enemy first then it doesn't matter if your armour can withstand 100mm or 20mm bullets.

In the gulf war, if you mounted the M1's gun and sight on a small 10 tonne vehicle it would have still slaughtered the Iraqi main battle tanks.

Thats why i think putting a big gun and sights on a lightweight vehicles can have many advantages.
This argument is just no argument unimportant how often it is stated here on several threads (No offense intended, we just had the discussion in the light tank thread and others :) ).

If you have to go against an enemy which is not totally dumb and there is not always great weather above a desert you have a problem with your theory.
Even during the gulf wars the Abrams for example took enough hits by Iraqi tanks.

And there are several occasions were air recon was not available due to the weather.

Now think about a terrain like in the Kosovo (There it was close to become a ground war).
Especially when you are advancing it is more than possible that it happens that the enemy gets the first shot.
A good choosen hull down enemy position in a terrain with scattered hills and woods can just not always be spotted before it is too late.

Or bigger clashes of mech formations. There it is not unusual that you may see the enemy but due to the amount of fire which is exchanged you get it unimportant how good your spotting ability is.

And then you will be happy about your armor.


BTW. If somebody buys the Puma you should exchange the 5.56mm coax with a 7.62mm coax. Whoever thought that this would be a good option is... :lul
 

Chrom

New Member
30mm Bushmaster gives you a weapon that can kill any enemy IFV we (the US) are likely to encounter in the near future.

Improved munitions can stretch this further.

25/30mm is good enough for the foreseeable future.

Larger weapons on western IFVs just aren't necessary, given the likely threats.
Omg, again. How NEAR that future you are refering? 3-4 years? Thats 1st. But there is strong 2nd : We dont speak about US ALONE! We are discussing GENERAL concept, what applies to MOST world armed forces. Of course, US can get away with just HUMVEE if they need - yes, losses will be slightly higher, but nothing major - US dont plan to fight with any capable opponent in the near future and so always can compensate weakness in area with overhelming strength in another. But not ALL countries enjoy such advantage over its opponents. And 3rd.. Your conception about "likely encounter" tends to quickly degenerate to "that encounter is unlikely BECOUSE we dont have IFV capable enouth for that enemy".
P.S. IF next year Iran buys 1000 BMP-3 - what will you say? - "It doesnt matter cuz we have kick-ass airforce?" Or Bush will retract plans attacking Iran becouse of that? Or he will send his soldiers on die in unsuitable IFV's against much better adversary?
 

Waylander

Defense Professional
Verified Defense Pro
Maybe we should leave the superpower a little bit aside. :)

There are enough possbile hotspots out there were the opponents are much more comparable and the ability to counter the enemy IFVs with your own IFVs could become a critical factor.
 

B.Smitty

Defense Professional
Verified Defense Pro
Omg, again. How NEAR that future you are refering? 3-4 years? Thats 1st. But there is strong 2nd : We dont speak about US ALONE! We are discussing GENERAL concept, what applies to MOST world armed forces. Of course, US can get away with just HUMVEE if they need - yes, losses will be slightly higher, but nothing major - US dont plan to fight with any capable opponent in the near future and so always can compensate weakness in area with overhelming strength in another. But not ALL countries enjoy such advantage over its opponents. And 3rd.. Your conception about "likely encounter" tends to quickly degenerate to "that encounter is unlikely BECOUSE we dont have IFV capable enouth for that enemy".
P.S. IF next year Iran buys 1000 BMP-3 - what will you say? - "It doesnt matter cuz we have kick-ass airforce?" Or Bush will retract plans attacking Iran becouse of that? Or he will send his soldiers on die in unsuitable IFV's against much better adversary?
You are trying to generalize a requirement for the rest of the world, without taking into consideration local geopolitical and military realities.

Everyone has their own needs. What makes sense for the UK doesn't make sense for Pakistan.

30x173mm appears to be enough for Germany and the US. 30x165mm is enough for Russia, China and other BMP/BTR users (though arguably it's not enough if they plan on fighting Western powers).

Other European nations think more is necessary.

Still other nations don't even use IFVs, nor do their adversaries. So for them, this entire discussion is meaningless.

There is no one-size-fits-all.
 

eckherl

The Bunker Group
Verified Defense Pro
@Chrom

One of the most ironic things that no one has stated in this topic is that Russia doesn`t even like the BMP-3, they would rather stick it out with a uparmored BMP-2 with the newer 2A72 auto cannon, Some Russian officers actually felt that the 100mm 2A70 gun was way to much firepower for a IFV, the seating arrangement is quite clumsy also due to the size of the turret. This Russian army was pretty much forced to accept it, and if they would of had their way they would not have it. 30 mm is going to be around for a very long time to come in the Russian Army and why not, it is still effective against killing other IFVs.
 

Chrom

New Member
@Chrom

One of the most ironic things that no one has stated in this topic is that Russia doesn`t even like the BMP-3, they would rather stick it out with a uparmored BMP-2 with the newer 2A72 auto cannon, Some Russian officers actually felt that the 100mm 2A70 gun was way to much firepower for a IFV, the seating arrangement is quite clumsy also due to the size of the turret. This Russian army was pretty much forced to accept it, and if they would of had their way they would not have it. 30 mm is going to be around for a very long time to come in the Russian Army and why not, it is still effective against killing other IFVs.
Hmm, nope. I never have read it from someone who really was in Chechnya. Yes, they blamed cramped seating arrangement - but they never ever complained about 100mm gun. Most soldiers are very happy with it. They also liked better protection.
Are you sure you dont mix it with BTR-80 / BTR-90 situation? Thats where many HIGH army generals really unhappy - BTR-90 is much heaver, cost 3x as much and very often redundand relating BMP's.
P.S. RUA had indeed no option but accept BMP-3. BMP-2 already showed its age, and BMP-3 was the only ready vehicle. Note, it would pose ZERO problems to manufacture BMP-3 without 100mm gun - but thats NOT what army wanted. They wanted better seat arrangment and escape doors - thats all. But it was nearly impossible to design completely new chassy quickly - so there was no choice.
 
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