Hello everyone, IS-3 is one of the more popular heavies in this game. It’s got the looks firewpower and armor to match it and when it comes to brawling, few things surpass tons of Russian steel. However, it has one catch – the BL-9 gun. Sure, the gun performs relatively well – it has massive firepower and while not exactly the most accurate gun out there, its penetration is very decent and especially with gold ammo it rocks. The problem with it is that the vehicle does not look historical with it. This is the setup with D-25T: And this with the BL-9 Now, BL-9 on IS-3 when it comes to historicity is dubious. I’ve read some info about it actually being proposed, but the gun pre-dates the IS-3 by quite a bit, so – who knows? I don’t know whether a prototype was ever built but there was at least a plan to do that, so it’s safe to assume that the gun is probably unhistorical, although, as a simply better gun, the BL-9 is used in most cases and only hardcore history fans use the D-25T voluntarily for the “authentic look”. Russian player Baronp in his post proposes to change that. This post is based mostly on his work. BL-9 was added into the game a long time ago as a way of improving the IS-3 performance, because on tier 8, the historical performance of the D-25T is not enough. Ever since, the developers changed their policy significantly (some of the worst unhistorical crap came in the beginning of the development and was gradually switched for more historical options) and thus it is possible to consider replacing the BL-9 with a more historical, yet also well-performing option. One of the more obvious (and also common) solutions to this issue is – instead of having unhistorical guns – to introduce more advanced/modern shells for historical guns and thus keeping the performance while maintaining a reasonable amount of historicity (a tank with a fake gun is – when it comes to historical realism – worse than a tank with a correct gun, firing shells available from 1960 or so). In case of the IS-3 there was this idea by SerB to do exactly the same thing – take the D-25T and replace the shells around so that the gun gains improved performance. This however was not related to the IS-3 itself. Originally, there was an idea to actually have the IS-4 with its historical (D-25T) gun only (!), firing advanced ammunition instead, at least that’s how SerB personally imagined it. It was tested and it did not work for one reason or another and the idea was abandoned, at least for the IS-4. But what if the same thing was applied to the IS-3? Currently, the penetration of the IS-3 guns looks as such: D-25T: 175/217/61 BL-9: 225/265/68 From here, the solution is somewhat obvious: put the gold D-25T gold shell as the silver shell and the 265mm penetration HEAT round (the ammunition between D-25T and BL-9 is compatible, the increase of performance from the same shells from BL-9 was influenced by longer barrel) as a gold round and there you have it: 217/265/61 sounds acceptable, does it not? Well, there is a catch of course. Both guns use the same ammunition! The silver shot is armor piercing UBR-471, the gold shot is a armor piercing BR-471D (in the game, it is implemented as a “subcaliber” round, but this is not correct and it is a known bug, that will apparently be fixed at some point). The increase of performance for both was not due to the properties of the ammunition, but due to the properties of the gun, most notably the barrel length. Simply put, if you make the BL-9 gold ammo, into D-25T gold ammo, the penetration of the very same round decreases from 265mm to 217mm. When you switch the BR-741D AP (“subcaliber” in game) ammo to the silver position on the D-25T, you have nothing to put as a gold shell. Or perhaps there is another shell? Yes well, this is another catch. Literature apparently mentions only three types of shells for the D-25T specifically (apart from the unusable ones such as HE, illumination shells, training etc.): BR-471 AP-T (sharp round without cap) BR-471B APBC-T (blunt round with cap) BR-471D APCBC-T Their penetration values can be seen in the following table (first column is the caliber, second the name of the shell, third the angle and then it’s penetration at various distances – asterisk means missing data): Direct comparison with the game data is not possible: first, there are no data for “less than 100 meters”, with which the game operates. Second, BR-471D shell has quite different properties from the game (ingame penetration at 500 meters is 204mm for the D-25T, in real life it was apparently 185mm). In any case, the table does not offer the answer to what we are looking for (you might have noticed the BM11 subcaliber round in it, but 320mm penetration at 2 km (450+ at 100m) is not exactly what we want in the game). The answer lies somewhere else. According to the data, compiled from Russian sources by Baronp, a shell exists, that could fit the profile for the gold shell. 122mm ZVBK5 (ZVBK6M) round, firing a non-rotating HEAT shell ZBK10 (ZBK10M). This shot is designed for the Soviet D-25TS and A-19 guns and its purpose is to destroy armored targets and bunkers as well. Round weight: 26,125kg Shell weight: 18 kg Muzzle velocity: 820 m/s Penetration: 400mm (any distance, 0 degrees) or 200mm (60 degrees) So, what we have here is a HEAT shell with a cca 400mm penetration – yes, that’s kinda OP for tier 8, but this can be balanced (as in, nerfed): many – if not practically all – later HEAT (gold) shells in the game have less penetration than they have in real life, sometimes by as much as 100-150mm. Obviously, you can’t introduce the shell into the original D-25T, that would screw up the game completely (imagine the IS on tier 7 firing this, hilarious), but what you can do is replace the BL-9 with another version of the D-25T, the D-25TA, which is visually identical (D-25TS is already distinctive), but it has some loading mechanism changes, which could be used to justify the rate of fire increase. And so, you get a gun that looks authentic on the IS-3 with 217/270 (? nerf)/61 penetration properties. By the way, this way the IS-8 could apparently be fixed as well. Sounds interesting, no?

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