British Sub-Caliber Ammunition Penetration when accurately implemented
• 37mm M6 APCNR (1097m/s)
[Little John Adaptor]
115mm @ 100m (0)
90mm @ 100m (30)
27mm @ 100m (60)
• 2 Pounder APCNR Mk.1 (1280m/s)
[Little John Adaptor]
138mm @ 100m (0)
108mm @ 100m (30)
32mm @ 100m (60)
• 2 Pounder APCNR Mk.2 (1190m/s)
[Little John Adaptor]
123mm @ 100m (0)
96mm @ 100m (30)
29mm @ 100m (60)
• 6 Pounder L/43 APDS (1151m/s)
[1st generation]
180mm @ 100m (0)
146mm @ 100m (30)
50mm @ 100m (60)
• 6 Pounder L/50 APDS (1219m/s)
[1st Generation]
196mm @ 100m (0)
159mm @ 100m (30)
55mm @ 100m (60)
• 77mm QF Mk.II APDS (1120m/s)
[1st Generation]
244mm @ 100m (0)
198mm @ 100m (30)
68mm @ 100m (60)
• 17 Pounder L/55 APDS (1204m/s)
[1st Generation]
270mm @ 100m (0)
220mm @ 100m (30)
76mm @ 100m (60)
• 20 Pounder APDS (1400m/s)
[1st Generation]
380mm @ 100m (0)
309mm @ 100m (30)
106mm @ 100m (60)
• 32 Pounder APDS (1540m/s)
[1st Generation]
472mm @ 100m (0)
384mm @ 100m (30)
132mm @ 100m (60)
1 Like
Isn’t the current speed of 1035 m/s roughly correct for the 77 mm APDS?
What kind of core does 6pdr APDS have? Can you give any estimate how effective it would be if added to the game?
I have always wondered why this round isn’t in WT yet because I could see it been really useful maybe around 4.0-4.7br with now Cromwell or other tank that has 6pdr.
According to this document the in-game speed is only barely slower than real life
It lists the speeds and penetration for both the 17 pounder and 77 mm APDS round (seeing as they are the same projectile). In-game the 77 mm APDS has a muzzle velocity 1035 m/s and this says 3400 ft/s which is 1036.32 m/s, while giving the 17 pounder APDS a MV of 3950 ft/s which matches the game at 1203.96 m/s (rounded to 1204).
Event then, APCBC shot is on the 77 mm compared to the 17 pounder is a 27% drop in kinetic energy (7.71 kg projectile, 883 m/s to 753 m/s)
The APDS having muzzle velocity of 1035 or 1036 m/s leads to a 26% drop in kinetic energy, while 1120 m/s leads to only 13%.
It just doesn’t seem to line up with how much weaker the 77 mm is supposed to be.
Unless, of course, there was some massive improvement to the APDS specifically on the 77 mm, which that graph doesn’t cover.
2 Likes
The 77mm APCBC should be 785m/s vs 884mm for 17 pounder
Seems to be the case after searching online. But that’s still a 23% drop in kinetic energy. 1120 m/s seems far too high for the APDS, and is incorrect according to the source above.
Nah I believe you that it’s actually the lower figure now. I’ll take official source over countless secondary sources
1036m/s for 77mm APDS
77mm QF Mk.II APDS (1036m/s)
[1st Generation]
218mm @ 100m (0)
177mm @ 100m (30)
61mm @ 100m (60)
1 Like
There’s really nothing to believe here, it’s just that I haven’t seen any source give a muzzle velocity of 1120 m/s for the 77 mm HV APDS.
On a side note, I did find one source that says it, being a book by David Fletcher on the Cromwell series of tanks.
However, at the same time this book also gives a muzzle velocity of 792 m/s for the APCBC, which from what I can tell is just wrong, not only because you’ve pointed out that it is 783 m/s, but also because I found a similar source to the graph I provided before that also says it’s 783 m/s (2575 ft/s).
While a difference of 25 ft/s from 2575 to 2600 is not the biggest discrepancy ever, it does show that the book is flawed to some capacity. So for now I’d just say that the Cromwell book is not very trust-worthy when it comes to the performance of the 77 mm.
One thing I do want to point out is that while the muzzle velocity for the APDS is 1120 m/s on the book, the 17 pounder APDS has higher 30º pen up until roughly 1500 yards, which matches the other graph I provided that shows that the 77 mm has the muzzle velocity equivalent to the velocity of the 17 pounder APDS at 1300 yards. In fact, the penetration values in general that are provided in the book for the APDS seem to roughly match the ones on the graph. This just makes it even more likely that it was just an honest mistake.
1 Like
Here’s something you might find interesting.
100mm 3BM-8 APDS penetration calculated using demarre and using 17 pounder APDS as reference
According to ‘Сустьянцев Колмаков Боевые машины уралвагонзавода танки Т-54 Т-55’
The penetration is
290mm @ 1900m at 0 degrees
~80mm @ 1900m at 60 degrees
2 Likes
I am a bit angry that 3BM-7, 8 and 11 are considered “gen 2” APDS simply because they have big nose pads.
Even from their own explanation, 3BM-7, 8 and 11 do not qualify for gen 2 slope modifiers.
It is also important to note the influence of the penetrative nose pad of the APDS shells on armor penetration. A massive nose pad made of tungsten alloys reduces the denormalization of the APDS shell in the front layers of an armor at large angles, and also helps to reduce axisymmetric forces when penetrating into an armor. But the use of a nose pad leads to an increased consumption of kinetic energy in the front layers of the armor, which is spent on its deformation.
The Russian 100 mm and 122 mm APDS rounds just have a big soft steel jacket in front of the core, not tungsten alloy. On top of that, the L28 nose pad has more than just a big tungsten nose pad. It has a double conical, blunt tip on the core, and the tungsten alloy nose pad specifically tilts to improve performance against angled armor. The Russian APDS rounds lack both of these qualities, on top of missing the tungsten alloy nose pad to begin with.
1 Like
@Laurelix what about this?
Definitive evidence for 77mm can get could very fast lol
It says the 17 pounder APDS goes only 3680 ft/s? That’s 1121.664 m/s.
It says 1120m/s for the 77mm on comet
I noticed, I was pointing out the speed on the 17 pounder APDS though. It says 3680 ft/s.
