What are the known penetration figures for these rounds ?Originally Posted by XTX-Horus
That being the case why dont they allow export of 3BM42M rounds ? I dont find 3VBM19 mentioned in rosoboron export list of 125 mm APFSDS rounds
The 3BM42 is part of the 3VBM17. The penetration value of the 3VBM17 is around ~450mm RHA which is very poor against modern day MBT's.
http://www.roe.ru/cataloque/land_for...for_35--38.pdf
3VBM19: ~650mm RHA @ 0 degree's @ 2000 meters.
3VBM21: ~600mm RHA @ 0 degree's @ 2000 meters.
3VBM23: ~800mm RHA @ 0 degree's @ 2000 meters.
Well, that question is an open ended one for me. Maybe someone else can explain.That being the case why dont they allow export of 3BM42M rounds ? I dont find 3VBM19 mentioned in rosoboron export list of 125 mm APFSDS rounds
http://www.roe.ru/cataloque/land_for...for_35--38.pdf
Really? That's some great penetration for a 125mm separated APFSDS. How could have they achieved such penetration without using a single-piece ammo?
Interesting figures specially for 3VBM23 , are any of the about 3 mentioned rounds DU rounds or all are Tungsten ?
Also how come 3VBM19 has a higher penetration figures compared to 3VBM21 ?
Before anwsering your question dear fmaster, i have to go into some detail to describe the APFSDS round that are mentioned above (your awnser is included in the description):
-3VBM19: The 3VBM19 is in every way, an improvement of the 3VBM17 due to using improved penetrator design and sabot (3BM42M and 3BM44M respectively for the 3VBM19 VS the 3BM42 and 3BM44 for the VBM17). The penetrator is made out of Tungsten.
-3VBM21: The 3VBM21 is a new design that uses the 3BM46 penetrator and the 3BM48 "Svinets" sabot.
-3VBM23: The 3VBM23 is an APFSDS that uses the 3BM46 penetrator but with an improved sabot (3BM48 "Svinets-2"). The improved sabot increases both muzzle velocity and energy conservation of the 3BM46 penetrator. The penetrator is made out of Depleted Uranium.
Hopefully that satisfies your curiousity.
Thanks for your explanation. However I was curious because Russian two-piece APFSDS rounds are inherently inferior to western single-piece counterparts due to their limitation of penetrator length which cannot be elongated more than the point where the penetrator meets the propellant. Then how could they improve their penetration to more than M829A3, the most modern US DU APFSDS which is said to have 700~800mm penetration, by just tweaking the sabot?
Just a hint, whether the ammo is in two pieces or in one piece doesn't make any performance difference.
That's simply wrong.
I don't know where you heard that fairytale, but it's wrong. The problem was rather in the limitation due to the lenght of the rounds the autoloader could accept.
Here's a chart I found, it may not be 100% accurate, but it's enough to give one an idea about armor and armor-penetration performance.
http://i.imgur.com/JWwdj.jpg
Last edited by Hyde; 04-15-2012 at 01:09 PM.
Nothing to do with two piece or one piece , the older autoloader of T-72/T-90 tanks could not fire newer longer rounds , the modified loader of T-90MS can fire those and the Russian T-90A can do as well , Although modification can be done on existing T-90 autoloader to fire longer rounds. ( L=740 mm )
Atleast the T-90S Bhishma cant fire the newer rounds due to limits imposed by its older autoloader
Here are some more technical details on 3BM42 rounds from a RFI floated by Indian MOD , they are ordering 66,000 3BM42 and 25,000 for Invar . The 3BM42 goes by designation AMK 339 by MOD
http://www.ciidefence.com/pdf/RFI/RF...FSAPDS-AMN.pdf
Caliber. The ammunition should be capable of being fired from 125 mm Smooth Bore Tank Gun of T-90 and T-72 tks.
Shelf Life Not less than 15 (fifteen) years under Indian Tropical Conditions. Specification with regard to explosives fillings with test procedures to evaluate the shelf life be made available to DGQA (Indian QA Agency). Literature substantiating the claim that explosive fillings would give stipulated shelf life need to be made available.
Technical Characteristics
4. The major technical characteristics are as under:-
(a) Round Designation of Mark - 3BbM17
(b) Projectile Designation or Mark- 3bM-42
(c) Mass of Shell or Shot (kg) - 7.05 kg
(d) Mass of Round (kg) - 20.4 kg
(e) Primer - GUV-7
(f) Designation of SCC - 4>K 63
(g) Increment Propelling charge - 9.50 kg
(h) Muzzle Velocity (m/s) - 1700
(j) Effective Range (M) - Not less than 2700
(k) Consistency group of Rds - HSD & VSD ≤ 0.35 mil
(l) Tracer - 3YPZM
(m) Armour Piercing Characteristic. The depth of perforation (piercing) in mm.
-
Prospective vendors to state details.
(n) Nominal Pressure - 440 M Pa
(o) Maximum Pressure - 530 M Pa
It seems that I was misinformed at some point around the autoloader. Still, I can't understand its penetration as the penetrator still appears to be kinda shorter than M829A3(800?mm vs 740?mm). Or are they using different methods to display penetration capabilities?
Just as with the number of pieces, you assume the wrong thing, the absolute lenght isn't proportional to the performance. Not saying it doesn't have an effect, it obviously does, but you can not directly deduce the penetration capabilites from the lenght of the sabot alone, the gun and propellant also play a part, and are which gives the round the energy in the first place. If it was the other way around, a "western" round which is shorter achieving the same penetration as a Russian round which is longer, you would take it for granted and attribute it to some imaginary superiority and sophistication in "Western" engineering.
If the round in question is longer and requires the new autoloader and is supposed to be used by T-90A or T-90MS and above, maybe the penetration figures were achieved using another gun, namely the newest 2A46M-5 or 2A82.
Penetration is a function of materials used, length to width ratio of the penetrator, construction of the round (how much energy is lost on the sabot for example), and the total kinetic energy of the round. Increasing penetration is not as simple as making the round longer. And anyway, the new upgraded T-90 autoloaders can accept rounds of up to 750mm long I think (thats not including the propellant charge).
I'm not saying that Russian technology is primitive. I'm a rather Russian weaponry admirer. I just thought that Russia might be quite more advanced in such areas like material engineering/metallurgy than the United States if they could achieve same penetration with some 60mm shorter penetrator as the lengthening the penetrator without breaking the balance of overall ballistic performance is the most critical factor for the penetration anyway, and Russian 125mm guns like 2A46M-5 has somewhat less chamber pressure compared to western Rheinmetall 120mm(at least I heard so. If not, please enlighten me).
Regardless, thank you all for the infomations.
Nope, you were saying that, because you've confused penetration ability with the penetrator length, while there's no direct dependency. There's a correlation, but that's it. There are many other variables in the equation, such as a mass of the sabot, powder charge, type of powder, all of which would determine a chamber pressure and thus (if you factor in the overall mass of the projectile, both sabot and penetrator) a muzzle velocity, etc.
Aren't you answering your own question here? Lower chamber pressure would probably require a longer penetrator to achieve the same ability.
The initial 2A46 gun peak pressure of 5100bar (on par with the M256 L44 gun of the M1A1), the 2A46M-1 and later guns have peak pressure up to 6500bar. This gun is in use since 1981 and on all the modern Russian tanks. So I'm not sure where you get the lower peak pressure idea from.
Posting Permissions
Reply With Quote