3x20=60. 60~=54

Sorry that doesn't work. The HRC has 6 shots per ton. That's 1 more than the AC/20 and 2 more than the PPAC/20. You can't say that the HRC has .75x the number of shots of the PPAC/20 has, when the HRC has 50% more shots.

AC9=100/9 = 11 shots per ton. 90/9 = 10 shots per ton if using ac/2 90 damage/ton.

PAC9=11*.75=8.25 shots per primitive ton (7.5 with ac/2 90 damage/ton)

Rifle9=8.25 *.75 = 6.1875 (5.625 with ac/2 90 damage/ton)

6.1875 or 5.625 ~= 6, and 6 shots is what a Rifle9 has.

There is no AC/9 or PAC/9 so I don't know what you're trying to prove there. Also, I don't know why the AC/2's ammo isn't 100 like the other AC/s but if you're trying to prove the HRC is a primitive AC/2, it doesn't work. Going by 90 points of damage, the AC/20 would still have 5 shots thanks to rounding. The AC/10 though would loose a round to have 9 shots and the AC/5 would loose 2 shots to have 18. That more closely matches the HRC's 6 shots, the MRC's 9 and the LRC's 18. Since AC/s have a greater rate of fire than RCs the damage AC/s do is greater. We can see that in the damage 3-5, 6-10, 9-20. In fact going by this the HRC is nerfed on damage and should do 12 damage. The MRC does twice the damage of the LRC but the HRC only does 50% more damage than the MRC. The AC's though double each time.

I see that.

The 75mm APCR round is 8.61kg. Rifles have 54 damage in 1000kg of ammo. You get 2 APCR rounds, spaced 5 seconds apart, with the KwK 75. Solve for 1 round of 8.61kg of damage please.

With each round weighing 8.61kg the KwK 75 would have 116 rounds per 1000kg. That's 58 shots (2 round bursts) weighing 17.22kg each. The LRC fires 55.55kg per shot. That's 3.22 times as much weight as a KwK 75 2 round burst. That would put the KwK 75's damage per ton at 16.77, rounding to 17 damage, each burst of damage doing .29 damage. 1 round would be .145. On a vehicle that'd round to 0. As a field gun, damages would be added together.

However, you are ignoring that not only the weight of ammo the LRC fires but the weight of other period weapons that I have pointed out before.

We do know that 5kg does 2 points of damage thanks to the Machine Gun. The KwK 75 fires 3.44 more ammo than a Machine Gun. So if the MG does 2 points of damage the KwK 75 would do 6.88, rounding up to 7 points damage per shot. With 58 shots, the Kwk 75 can do 399 points of damage per ton.

If you don't like the MG comparison how about the Infantry's Heavy Recoilles Rifle. Each round weighs 4 kg and does .57 damage, rounding to 1 point of damage.

A 2 round burst from the KwK 75 weighs 17.22 kg. That's 4.3 times more than the HRR round. Going with the unrounded .57 damage the Kwk75 should do 2.45. If one felt charitable that could round up to 3 points. With the rounded damage the Kwk75 would do 4 points of damage. I prefer the 3 points but even 2 points is better than 0.

We also know that the LRC fires 55.55 kg per shot while the Thumper fires 50kg per shot. If the LRC isn't firing a single artillery round then it must be firing a burst of rounds. That's 6.45 rounds of 8.61kg rounds. If a 2 round burst of 17.22kg does .29 damage than a 6 round burst of

51.66kg would do 0.87 damage, rounded to 1 point. There are the other comparisons of course. If 17.22kg does 2.45 damage than 51.66kg would do 6 damage. And if 17.22kg does 6.88 damage than 51.66kg should do 20.64, rounded to 21 damage.

I'll admit that 21 points of damage seems silly from a pre-1950's cannon. Not impossible but it'd really depend on the rate of fire. I think most 75mm cannons would do between 1-3 damage with 4-6 damage being less common but not impossible. Of course this means that they'd all have different modern equivalents. The Sherman's 75mm may be equivalent to the Heavy Recoilless Rifle while the Kwk75 may be equivalent to a LAC/2 or a PAC/4.