This is one area that I have come up with a blank. While there was APDS for the 77mm, I have seen no mention of it being used in WW2, the Comet itself only being post Bulge. I would give 77mm APDS a TK of about 23 and while I am thinking about it I would up the 17lbr (76LL) APDS to 26 or 27. Though I am not saying the 77mm APDS was NOT used in WW2, until I read otherwise I would strongly advise against it being available in WW2 ASL.
Found this on wiki:
6% of an average load? Works out to be about A3 in ASL parlance.
The axishistory.com and the other article giving 20% of all AP being APDS would mean 12 rounds (or 4 for 6%). Soviet T-34/76 usually had only 3-5 rounds of APCR yet get up to A6. Going on the Low Ammo numbers [B(#)] for vehicles like the Hummel, you should be talking about a 9 but allowance should be made for non "bread and butter" ammo types, so a D7 would be indicated. However there is also the overlooked fact that most tanks only had about 1/3 of their ammo load as AP. Let's say 20-24 AP rounds, so 4-5 APDS rounds, even with 50/50 between HE and all AP types then 24 AP and 6 APDS.
Indeed almost all tanks should have AP9-10 at best, but that would really slow down the game. The only exception would be tanks that carried mainly or only AP or had in the order of 90+ rounds. Tanks main prey were infantry and artillery, not other tanks. So you could be looking at 40 HE, 5 APDS and 16 AP rounds or thereabouts for a Comet. So if that 20% is even half right then APDS seems to be almost a "bread and butter" type, so should get it's D# bumped back up to D7 going on the T-34 example or D9 going on the Hummel example. A D7 or D8 would seem reasonable.
I suppose that part of the reason ?# (A5, HE7, D6, etc) are low for the same number of rounds as a B(#) is that being rare rounds they might not get any, never mind getting only, say, 6 rounds. However until I read otherwise, no APDS is my best estimate.
