Currently in game, AP rounds are more likely to bounce against sloped armour than APCR rounds. If you don’t believe me, take a look at the stat card and it will say 50% chance of bounce against armour at 60 degrees whereas APCR gets only 50% chance of bounce once the angle is 70 degrees. This means AP bounces more against sloped armour than APCR which should not be the case considering it denormalises less than APCR.
Moving on… Non Capped AP rounds tend to deform against thick flat armour since they lack a piercing cap to absorb the initial impact by transferring the shock from the tip to the body, hence protecting the penetrator tip and increasing the ensuing penetration. The issue is that gaijin is using AP slope modifier found in WWII Ballistics: Armour and Gunnery with the post deformation penetration of AP rounds at 0 degrees instead of the true full penetration potential value at 0 degrees which matters because at high obliquity plates, the impact shock is lower and the shock hits the body rather than the tip flat on hence why deformation of the penetrator no longer occurs. Due to using lower 0 value to calculate sloped penetration, the sloped penetration figures end up being too low against sloped armour.
For Example According to the British the full true penetration of 2 Pounder AP (40mm, 1.08kg penetrator) at 792m/s is 90mm at 0 degrees.
If we use this as reference in Demarre Equation for 90mm T33 APBC which is a 10.61kg penetrator + 0.3kg windshield at 853m/s, the full true penetration of this round is 215mm at 0 degrees
T33 APBC penetration according to Terminal Ballistics is only 165mm at 0 degrees at 853m/s, however this is with deformation of the round included. War Thunder Penetration Calculator gives it 175mm at 0 degrees.
HOWEVER, Terminal Ballistics ALSO rates the 90mm T33 to penetrate 97mm of armour at 55 degrees at 853m/s.
Now we will see which of these 0 values is accurate in calculating 90mm T33 AP(BC) sloped penetration at 55 degrees.
165mm (Terminal Ballistics Volume III)
175mm (War Thunder AP pen calculator)
215mm (Full Potential penetration, Brit criteria)
According to Terminal Ballistics, the 55 degree penetration at 853m/s is 97mm which gives the 90mm round the capability to penetrate Panther Upper plate past 1000 meters.
T/D Ratio (Thickness Divided by Diameter)
97mm / 90mm = 1.0777
So 1.0777 T/D ratio at 55 degrees gives us a slope modifier of 2.21
97mm at 55 degrees x 2.21 slope modifier = 214mm at 0 degrees.
CLEARLY, the correct number to calculate AP sloped penetration is the full penetration potential value rather than the penetration at 0 degrees after AP shell deforms, because at high obliquities when it does not deform it does reach its full potential. The achieved penetration at 0 degrees after the round deforms DOES NOT represent the true penetration capability of the round. Using 165mm or 175mm instead to calculate sloped penetration at high obliquity will only yield underperforming values because essentially all that gaijin is doing is making non capped AP rounds deform equally as much at high obliquity as when they strike thick flat armour at 0 degrees, hence why currently AP shells underperform in WT which means non capped shells like T33 AP(BC) can’t penetrate Panther Upper Plate like it should and could do in real life and when you add that the unreasonable RNG value of 50% chance of bounce at 60 degrees, it makes AP rounds feel like Popcorn Dispensers instead of actual capable Penetrators against sloped armour where they should be excelling.
According to US tests in a declassified report from November 1951 ‘Comparative Effectiveness of Armour Defeating Ammunition’ it states the superiority of AP shells performance against armour sloped at higher obliquity compared to APC shells however also the superiority of APC rounds against flat armour compared to AP rounds.
APC rounds feature piercing cap at the cost of a smaller penetrator resulting in lower kinetic energy and upon impact some of the energy is further absorbed by the piercing cap against the sloped armour yielding inferior performance to the AP round. AP rounds do not have the piercing cap hence why their penetrator is bigger and also there is no piercing cap getting in the way of the armour and the penetrator. However despite the fact APC round have smaller penetrator, the piercing cap stops the penetrator deforming against thick flat armour, increasing the ensuing penetration, yielding superior flat penetration compared to non capped AP rounds.
Full Source Here:
Changes that should be made:
Non Capped AP / APBC rounds should no longer deform at high obliquity. 0-37 degrees they should deform like normal. 37-53 should be the middle ground, from 37 to 53 the deformation should gradually become less and less as the angle increases and anything after 52 degrees, the sloped penetration should be calculated using the “full potential penetration” which is 215mm for T33 APBC at 853m/s or 90mm for 2 Pounder AP at 792m/s
As for those who still do not believe that T33 AP(BC) is capable of over 210mm penetration.
90mm M82 APCBC at 853m/s in WT has 185mm at 10m penetration
90mm T33 APBC - Look how much bigger the penetrator size is compared to M82 APCBC, the penetrator not only is longer than M82, it has no HE filler cavity inside, further increasing the penetrator volume and weight which increases the Kinetic Energy of the round.
It should be no surprise that 90mm T33 APBC penetrated Panther upper plate (80-85mm at 55 degrees) reliably at 1000m, whilst the M82 couldn’t whatsoever. T33 AP(BC) penetrator is literally 2.78 calibers (250mm) in length compared to M82 APCBC penetrator length at only 2.413 calibers (217mm). Also again I want to emphasise the fact that instead of a big non penetrator cavity filled with explosive filler that M82 has, the T33 is a full on solid penetrator slug without a cavity that could of been a penetrator, again reducing the actual overall weight of the penetrator on M82, and T33 having a much heavier penetrator.
Successful penetration of Panther Upper plate with T33 APBC
full source here:
Non Capped AP rounds chance of bouncing is far too high, 50% of the time at 60 degrees makes no sense. They shouldn’t be prone to bouncing more than APCR. Considering WWII ballistics slope modifier doesn’t put AP/APBC at 4.0 slope modifier until 68 degrees at 1:1 T/D ratio, I don’t see why gaijin can’t increase the 50% chance of bounce probability to 68-70 degrees instead of 60.
If you’re still not convinced for fixing the rounds, then here’s another reason. It would add another skill element to the game, knowing when it’s better to use AP round and when it’s better to use APC round instead of just using APC 24/7 because it’s better in every regard over AP rounds in game right now.
To support the overhaul give us a thumbs up on the bug report