3) The advantages of a smooth bore gun are well understood, now that Indian Mil-Ind complex has necessary know-how, they are shifting to smooth bore for Arjun.
. This take the cake.
Sanku Maharaj Ji has been maintaining until now that the minuses against rifling is that they are more difficult to make and more expensive to produce and maintain! Now how is that that the Indian "Mil-Ind" complex had the necessary know how to produce a more "complex barrel" than the simpler and cheaper smooth bore and went ahead to produce it, but are now shifting to smooth bore because, they now have "know how" ..indeed how, by dumbing down themselves?
. Another imagined and lets say inspired fiction writing by the Maharaj!
Ah.. Advantages of smooth bore are "well understood" indeed. From times that cannons were created (go take a look at the old cannons in museums around the country), they were smooth bore for a few hundred years ! Rifling came in much later and became prevalent because of it's advantages.
Now Maharaj goes "back to the future" to "understand advantages" of a smooth bore , as if folks didn't know of it all this while!
HEAT is not effective when fired from rifled barrels unless you add slip rings. This is because the HEAT jets get dispersed due to spin. HEAT has to be stabilized somehow. This can be done by making them long, making them sub-caliber and adding fins and a Sabot. But that reduces effectiveness of HEAT because the penetration is proportional to the diameter of the HEAT metal liner. (That is why you have the bulbous head in hand-held anti-tank rounds). You can make HEAT bulbous and stick out of the front of the tank somehow and fire it, but for enough range, it should be rocket propelled rather than an explosive cartridge propelled. Which suits hand-held anti-tank weapons but not tanks.
I had posted on precisely this in the earlier armor threads on why the HEAT from smooth bores suck and suck hard. Heat works best with a big bulbous diameter. The best you can have is the full diameter of the caliber. The French AMX-35 fielded exactly such a round, the Obus-G (google for it), a full bore HEAT round that had the slip rings to prevent it from spinning and was the Main Round and primary anti tank weapon, until the LeClerc was fielded (with a smooth bore I should add, primarily for Nato Ammo compatibility reasons, though just like the L7 and the AMX-35 gun, the LeClerc could "theoretically" fire Nato, but in practice insisted on French only). That must have been the ultimate tank fired HEAT round until now I think.
d. The reality is that we are stuck with thousands of tanks with smoothbores and that is the direction we probably have to go.
I am not sure of that though. The problem with that is if at all you have to "standardize" on a smooth bore, it has to be the Russian 125mm on the T-72/90 with all the inherent problems of limited sabot lengths (because of autoloader size restrictions), no unitary ammo (charge and shells are separate), it has autoloader , a tinder box if hit etc.. etc. The smooth bore on which it will make "sense to standardize", given the logic of installed base, is simply obsolete and has ZERO potential going forward.
From all indications, the next Russian tanks might well have a 125mm, but will have a bustle mounted loader for new long sabot rounds and newer ammo which simply cant be backward compatible with existing T series! So that is a dead end .
It does not make sense to put the T 72/90 gun, carousel loader and death trap tinder box ammo storage on the Arjun or future tanks.
And if you are going to replace the autoloader and turrent on the T series, it is practically a new tank. You might as well go for the Arjuns and if indeed, there is a case to keep the T series chassis and still upgrade the turrent and ammo, why go to the Russians at all, when you have a perfectly and highly competent solution that you have developed for the Arjun..
You may not know, but I was probably the first on the forum to predict that Arjun will move to smooth-bores, and why. And this was much (2 years?) before the news came out
. What news , and where ? The bins along with the Mayan prophesy and Elvis Born Again and Coming of the Messiah kind of predictions!
Of course, but then GSQRs were primarily written in 70s, by which the clear advantages of smooth bores were not fully understood all over the world. Also the GSQRs were closely on lines of "previous and old" experience with British tanks which were rifled. (added later --> ok before you jump on me again, the tanks were not rifled, their gun barrels were)
. Great fiction writing. The Arjun project itself was probably not conceived in the 70s in the current form. The GSQR itself went through multiple changes, including a biggie of change in gun spec from 105mm to 120mm , and no change in reqmt to smooth bore! It is funny, that the IA/DRDO knew of the trend to 120mm, but not towards smoothbore and this couldn't be anything but a considered decision to retain the rifled gun. As for experience with the "previous and old" and hence not aware of new, I am pretty sure that the IA and the Defense R&D folks in the 70s knew perfectly well about the trends. After all,they did attend conferences, exercises and subscribe to journals and knew far better than the pre internet and Google warrior Maharaj days , who I suspect wasn't even born in the 70s or was at best a toddler back then.