Deck Gun Caliber
 

The type IX and the type VII have different caliber deck guns. My experiences are that they are pretty much the same. Are they?

it depends if your referring to them in RL terms or gaming terms.

In RL the VII was 88mm and the IX was 105mm.

10.5cm/45 SK C/32
Shell weight: 15.1kg
Firing charge: 4.08kg
Burster charge: 3.8kg
MV: 780m/s
Range: 15,175m (not that they could hit anything outside of about 1/4 of that)

8.8cm/45 SK C/35
Shell weight: 9kg
Firing charge: 2.1kg
Burster charge: Unknown, but a lot smaller than the 10.5cm
MV: 700m/s
Range: 11,950m (with same caveat as above)
http://www.navweaps.com/Weapons/WNGER_Main.htm

As you can see, the Type IX's deck gun has a heavier shell, so it carries more momentum; a larger firing charge, so it leaves the gun faster, both of which combine to give it a longer range.

The shell weighs more so it does more damage even if it doesn't explode, and a larger burster charge so it does more damage when it does explode.

But, as Jim said, none of that real-world stuff means a thing if it isn't programmed into the game. I don't know if it is or not.

Gamewise, I find that the 88 will sink more ships with the ammo provided than the 105