Zill and I ran a few matches with the gun on his galleon. Had the gun on the 1 slot in the ship loadout.
I had a blast with the gun. The damage might seem low, but upping the damage would defeat the point of bringing it which is of course to throw off an enemy charge or barrage. While I did find the reload and fire rate slow and long, making it any bit faster would make this gun too good for it's main purpose.
However, I do see some concerns, the range can probably be nerfed a bit because it's insane to think it can hit at 1800m reliably with heavy clip. Note the range is a little over a 100m more than either lumberjack or heavy flak. Those guns have decent shell travel times and shell arcs. The minotaur is raycast and all you have to do are load heavy and figure out proper leads. I'd say give the gun range something short of hwachas.
Another concern is the potency of the gun's effect. My last match of the evening, I was able to save us from a charging gat/flak pyra by turning it 180 degrees allowing the engi to keep a fragment of hull armor and a strand of our remaining health. It took two shots to accomplish. Even one shot during my other matches could cause enough trouble.
My final concern is the gun's arc. I believe the arc needs to be nerfed too. They're 45 degrees in all directions. While I can assume those arcs were given because it gives the gunner greater freedom to aim the shots more precise to allow for maximum effect, I found it far too easy to throw off ships.
TL;DR = Love gun, but needs some nerfs.