I love this tank ! But I am a bit worried by the effectiveness of the 90mm 1926 gun using only explosive ammo. I am sure it will be like the AuF1, at a high BR but with only explosive ammo doing nothing against armored vehicles. But I still want it at 100% to see it. AND AND AND… Follow my logic :
The ARL 44 uses a 90 mm SA mle. 1945 gun. The 90 mm SA mle. 1945 gun is a derivative of the 90 mm mod. 1939 gun, and the 90 mm mod. 1939 gun is a derivative of the 90 mm Mle 1926 (you see where it is going). The differences seems to be the length of the barrel, the fixations and the gun muzzle.
Do you think there is a world where the gun of the FCM F1 can fire the same shells the gun of the ARL44, as, at the origin, it is the same gun with what is appears to be the same breach and the same tube ?
The gun did have an AP round developed for it during WW2. Figures on it have recently been obtained from archival finds, which OP is aware of. He just hasn’t edited the post yet to include them. He was concerned that Gajin would use the AP round (which has decent performance when plugged into the calculator) to justify putting the FCM F1 at a BR where its armor no longer works.
I mean it has KV-220 levels of armour so unless it’s put to like 6.7 (which it obviously wouldnt) it would still work.
With 90mm AP I see it as 5.3-5.7 material, where it would suffer due to lack of speed. Turrets would be huge weakspots, with just 100mm of armor, penetrable by most TDs starting from 2.0 (rarer examples with 1.3). And Fourche still hasn’t provided me the full info on the shell, I only saw some side talks about it. However I was doing research with some other fellas and the incendiary naval 90mm shell may have been appropriate AP analogue - essentially armor piercing shell with incendiary head, like 37mm armor piercing shells were. So we have two options on sight, except I haven’t seen proper info on any of them.
I mean it depends what the shell would look like in game but I think its armour would be still good for like 5.0-5.3. The turrets are flat but also have the same armour on the sides so they can be very well angled. Also 24 kph is not that slow vehicle such as this, I mean it is better than something like black prince or churchill VII and dont forget it would be pretty much impossible to oneshot it.
But in the end it’s hard to guess when we dont know the shell performance. Also is there any info about its gun elevation/traverse speed and reload time?
+1 as long as it gets AP for the big gun. Otherwise, might be awful.
+1 for the mega goober
Here’s the fabled AP round. It’s an 11.2 kg APCBC round designated 90-40-1.
Depending on which 90 mm the FCM F1 gets (since 3 different 90 mm guns were considered), the velocity could be 750 m/s or 820 m/s. This yields 165 mm and 187 mm of penetration respectively in the DeMarre calculator.
We have found the holy grail of information
+1 for sure.
I wonder what is explosive filler as it plays a fairly significant role in what pen the round might have.
Otherwise gun’s performance gonna be comparable to that of American 90mm, which is wild for a tank like… this
According to the blueprint this APCBC uses the same shell as the HE shot we already have all the data on (And which is already in game). Note the line of vertical text to the left of the centre of the full shell blueprint on the left page:
Montage de l’obus explosif en acier de le 90 mle 1939
Which translates to:
Assembly of the 90mm steel explosive shell mle 1939
Now I am no expert on artillery metallurgy but it seems like this APCBC is quite literally the HE shell but with an added armour piercing cap (and ballistic cap).
Yeah, I saw that too.
However, what we have in-game is model 1925 HE shell (I haven’t fiund a vessel with 90mm cannon more modern than model 1926).
Idk if the one we have in-game is the same as model 1939, but if it is indeed so, I wonder what should be the penetration value for it. If it is modeled after the one we have, it should have 906g of TNT and a penetration of 123-140mm point blank, which is bonkers considering the filling being able to overpressure practically anywhere if round succeeds to go through most of the armor.
The only difference between the Mle 1926 and the Mle 1939 is that the latter had a barrel that was 1m shorter. There are no differences in the shells used as far as I could find.
+1
One look at this thing and you can tell that it’s french
By December of 1939, APHE development was canceled. The armor piercing projectiles of this program were all to be solid shot.
The plans for 90-40-1 are from a few months after this decision, and it would show the cavity if there was one.
The part of the blueprint referring to the HE round was in reference to the assembly of specific section of the HE round. This is likely just part or design commonality between the APCBC and HE where possible. Probably also some logistical factors involved in wanting to have a uniform process for creating both rounds for the gun.
I’ve also got specs on the Mle.1939 HE round. It weighs 10.86 kg with an explosive mass of 1.43 kg, which is likely TNT. For this round, it seems they opted to lower the charge quite a bit, so the velocity is just 350 m/s.
For a 90 mm round, that is a lot of filler, so it could have some respectable HE penetration
(~20 mm)
Nice findings.
But am I getting it right: 90-40-1 was still 820 m/s, even tho the HE mle 39 had 350 m/s?
I also wonder how come the APCBC weights about 400g more considering caps overall weight ~1.4kg (doesn’t line up with 11.2kg of the round mass). Does it mean something was done to the HE shell, like the changing of fuse or something as it made a bit more sense with mle 25 HE that weighted below 10kgs
EDIT: also, if my calculations are right, even with 1.43kg of explosive filler, penetration will be around 140 mm point blank, which I sort of doubt is true
Yes, 90-40-1 had a velocity of 820 m/s with the Mle.1926 or Mle.1939 gun. It was 750 m/s on the shortened Mle.1939 gun. Mle.1939 HE had a velocity of 350 m/s since they used a heavily reduced charge.
Also, see the post I made just before the HE round specs. 90-40-1 is solid shot APCBC.
Oh, missed that part. Thanks.
Spoiler
Pity it wouldn’t be the funny, skill-less, lobotomised round to oneshot KV-1s wherever it lands on it
You know what they say. The French copy nobody and nobody copies the French.