First, to answer about the OFL 120 F1 and OFL 120 F2:
- OFL 120 F1 has been correctly reported. It’s currently slightly underperforming (some sources claim around 600mm of pen), but this is explained by the game’s use of the L-O formula for APFSDS penetration. Most high-velocity APFSDS are somewhat underperforming using this assumption when compared to real life (and the OFL is one of the fastest shells, I believe). So as far as in game goes, it’s actually correct. I will probably be corrected on this, but the dm53 is also visibly underperforming
- OFL 120 F2 also has enough information to use the formula, and it would end up with 1mm less penetration at close range while retaining better penetration at long range. This is also due to the formula not being accurate for DU shells. This is common across all DU APFSDS already in the game.
In real life, the OFL 120 F2 is visibly capable of retaining the penetration of the OFL 120 F1 at 1 extra kilometre in distance.
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As seen in this screenshot, the manufacturer of the French APFSDS claims better penetration for the DU shell as well
The only shell that would bring better penetration is the Shard. There have been attempts to find enough information to use the LO formula, and I believe some people have estimated it in the game at around 650mm plus or minus 20mm.
The armour of the Leclerc is another discussion.
The Leclerc tested in the Swedish trials didn’t use the final production armour. In fact, when the French army received their first Leclerc in 1991, they weren’t impressed with its armour either. GIAT had to make some changes: transmission had some issues, reliability, and armour as well. The Leclerc used in the Swedish trials is a tranche 1 or 2. The French in-service Leclerc received the S1OP package by the time they entered service in 1997, which is basically an S2 without the A/C.
As for the S2 armour, it has received some extra thickness, which isn’t represented in the game on the turret, meaning that all Leclercs are underperforming here. This is clearly visible when looking at pictures.
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This is the armor of an S2, as we can see, there’s an extra thickness at the edge of the armor. This is neither present on the S1 (pre S1OP) nor in any Leclerc in game
For the hull armour, the 420mm value was taken from a trial that did not actually test the armor (only the Swedish trials did any testing on them, and from those trials, only the turret armor leaked). It could very well be a low estimate. I am not sure that the armor testbed Leclerc was already tested at that point. The one known thing is that the Leclerc was tested against its own ammo (range and actual testing conditions are unknown), and armour should at least be able to defeat it at a reasonable range (let’s say under 1-2km), meaning it should be protected to around 500-550mm at least, and as what was found during the Swedish turret trials, which also happens to at least prove that the 420mm from the British trials were at least a low estimate, or simply that armour improvements did happen between the prototype that was tested by the British. Also it is to note the Swedish did not consider an armor upgrade of the hull necessary, and their requirements are known
As for chemical armour, a UAE Leclerc (that uses an S2-derived package) was hit by a Kornet, which was stopped after penetrating a fuel tank (another ATGM did kill the driver, which shows that there is a weakspot on the driver side). In game a kornet would achieve full penetration if not actually over pressure the tank by hitting the UFP. The thing is, whether we believe this or not, the upper front plate is massively underperforming, and armoring from 420 to 550 wouldn’t save it from top-tier rounds but at least make it resistant to autocannons, HSTVL, and 2S38. but, as it always goes with the Leclerc, there is insufficient evidence for the actual effectiveness of the S2 and later armour packs. For example, the S21 turret is claimed to be able to withstand « next-generation APFSDS, » but good luck arguing with that.
As for the titanium add-ons, some things are claimed: The Leclerc S1 hull features titanium (probably for the fuel tanks lining), and some claims made by Marc Chassillan, who is currently considered a secondary source (since he often gets things right, but also sometimes isn’t completely correct, such as for the turret rotation speed).
As for the often found argumentation of “composite can’t have better than 1 KE coefficient, hence Leclerc can’t have decent KE protection” : In the late 1990s, France and the USA cooperated on high-density ceramics which demonstrated that they could obtain a KE effectiveness of over 2 for the same weight as RHA, when tested against APFSDS. This was likely used on SXXI. But then again, there’s a missing link that would allow to confirm this completely
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Thanks Mulatu for the different elements give (Swedish trials, Ceramic testing, S1OP configuration…)