ORIGINAL: Telemecus
Crackaces spent ages testing this on message level 7 and pretty much came up with that conclusion. Lower calibre guns are better attacking in the open OR defending (which seems to always have the attacker in the open) as they have a much greater rate of fire. Nebs/Rockets seem to be like low calibre guns no matter what their size. In the case of the Axis the neb regiments might be preferred only because they are one of the few regimental size indirect fire units so the number of "tubes" makes up for the lack of blast. But yes once you are onto forts etc you need the blast from larger calibre guns. You can see a pdf about this in post 729 here
tm.asp?m=4250683&mpage=25
Also they found that anti aircraft guns of all calibres, not just the 88mm, are effective in ground combat. I was sceptical that this was true historically as I assumed you would want to use an expensive quad cannon on expensive aircraft - not cavalry say. But timmyab found this video
https://www.youtube.com/watch?v=48zE-hRAYEA that actually describes the use of German anti aircraft guns in a ground role - and the manufacture of munitions for them to do this. So the game engine is right to say that anti aircraft guns are also effective in ground combat.
Great link!
I am not sure the
RoF works as described though (that having 12
RoF will mean 12 shots taken). I think it is more of a modifier, which will affect the chance of the gun taking another shot. Something like: Gun will take another shot if random(x)*Previous shots < 10 +
RoF.
So the German LeFH 18 105mm gun with a
RoF of seven would get a second shot if random(x) < 17 and a third shot if random(x) < 8.5.
Meanwhile the 20mm Quad (FlakVierling, I think it's nicknamed) with a
Rof of 400 would automaticaly get 40 shots off before even a roll of 10 would stop it from firing again. Quite deadly against infantry in the open.
This also fits the guns with a
negative RoF. The German 600mm Geraet 040 mortar has a
RoF of -10, making it impossible for that gun to get off more than one shot pr combat if using theabove formula. If simply assuming the
RoF is the number of shots taken in combat, this gun would never fire.
All this is obviously just guesswork on my part, since I have no idea what the actual formulas behind the game code is.
As for using AA in ground roles, the Germans especially excelled in this capacity designing most of their AA guns with optics and low enough traverse to be used in ground roles. The obvious example is the 88mm gun, but most other AA guns were used this way as well.