About tank guns and amunition, hope it will be interesting topic :-)
In penetration data I will base on russian sources -they are ussaly most credible (the best). I will ussaly give value for monolith steel plate slopped on 60@ - it's the best scenario for APFSDS penetrator. In sucht scenario (slopped on 60@ plate) penetration value can be bigger at even 17-20% then on 0.degree plate - this is caused by "asymmetry loads back surface" of the plate):
penetration at 2km, on plate slopped by 60@: 540-560mm RHA:
DOI - 1989 (in some sources - 1988)
penetration: at 2km, on plate slopped by 60@: circa 700mm RHA
this round was to weak to overcome T-80U and T-80UD and T-72B m.1989 whit Kontakt-5 ERA, what was "suprisly" discover on tests in circa 1994. The same story was whit DM43 prototypes..
DOI - 1992
penetration: at 2km, on plate slopped by 60@: circa 740mm RHA
Fist US round whit composite sabot.
(lack good photos)
insted of this:
KE-W so M829A1 but whit WHA penetrator, and KEW-E3 so M829A2 whit WHA long rod.
DOI - 2003
penetration: at 2km, on plate slopped by 60@: propably circa 800mm RHA, but is not sure value,
round devleoped to everpas heavy ERA but whit unkown result
DOI -2016 :-)
penetration - no idea
It's very interesting round
data link is for APFSDS round?!
I have a hypothesis...
Ok so it have data link to be programmed, it is said to be capable to defeat 3rd generation heavy ERA (Relikt, Knife, etc.) and active protection systems (hard kill). It seems that focus is primary on defeating heavy ERA. But then again, why do you need to program just a long rod fired by a big gun?
There are few options:
- Gudining the round,
- "Intelligent" control over propelant charge ignition (dependant on propelant temperature, environment temperature, gun service life, range to target etc.)
And truth to be told hypothesis that there is some sort of precursor in the rod is the only hypothesis that makes sense. Control over propelant charge ignition is not needed and probably not possible at all with current technology, besides the M829A4 (and all newer US ammo types for 120mm smoothbore) use insensitive propelant charges. And it is nowhere mentioned in any document avaiable for public. Guiding the rod to target? Perhaps possible from technical point of view, but why? Again it was nowhere said that FCS for M1A2SEPv3 have ability to guide any type of rounds. And manouvering of the rod during flight means loss of a lot of energy, even if this manouvering would be done to "cheat" the APS for example.
So perhaps the option is to somehow use a precursor that is "fired ahead" of the main rod.
So how the rod designs looks like here? The rod is made from two segments, the "precursor" and the main rod behind it. How they are connected? it might be some sort of polymer, glue that can be weakened by heat and the release precursor, and during flight rods heat up pretty nicely.
The precursor can also be relased based on a simple difference of speed between it and the main rod, and main rod can be slowed down by some sort of additional fins (aerodynamic breaks) released at specific point programmed by FCS. In such case precuros would initiate ERA and the main rod would have a clear way to main armor of the target.
How to cheat APS tough? Counting that precursor will be qualified by APS as threat and APS will be initiated, creating a time gap in APS reaction so it won't be able to counter the main rod? Possible yes, but then there is question, if APS will just not ignore the precursor, and this might happen, now of course there is a question how dangerous is precursor itself? For a MBT or vehicle with similiar levels of protection, for it's front it won't be dangerous in most cases, sides? If they do not have any addon armor, very possible. For lightweight platforms, yeah precursor also will be dangerous.
Of course these are only hypothesis, and we will see if other nations will also design APFSDS rounds with data link. Then we might get closer to the truth. Right now, treat it as food for thoughts.
of course this data link coud be placed only for security resons, as one person on TankNet had wrote:
ps. prefragmentet APFSDS during flying exist now, as smal-scale models and test object:
Neat video showing off how HEAT shells work. The guy detonates 4 charges, one that's just explosive, one with explosive that has an indentation in it, then one with an explosive that has an indentation in it that's filled with metal, and finally, the same charge as in part 3, but at a small offset to focus the blast.