I was thinking about another stationary kind of gun tht isn't a piece of artillery. It would resemble a Browning 50 caliber, but okay here is the idea.
You take the PK and M60 machine guns and put them on their bipods and make it like the MG west or MG east guns. You have to get in the gun and it can't be moved or maybe not. You could drop all your weapons and carry the big gun around with the bipod out but I think it would be better stationary. You could also make a gun that is using the bipod and is placed on top of a sandbag wall and the gunner knels behind it.
It wouldn't be as exposed as a browning nor would it have such a slow firing rate.
Whadda ya think?