[Imp]

Your comment about HMGs made me look not like you to get things wrong.

1) All weapons regardless of type use one ammo per fire.
2) Hexes effected per fire is the max assumes wildly inacuarte, double MMG for instance normaly hit same or adjacent hexes for 7-10 effected.
3) Infantry can effect up to 3 hexes if in range & have 3 Z fire capable weapons, assuming 4th is grenade so could Z fire with 4 weapons adjacent.
4) Double HMG therefore can effect 2X7 overlaping hexes & an arty piece 1x7.
Both can also effect one more hex if in rifle range.

They seem to work about right in my book get the odd map where MMGs are worth their weight in gold stopping you cold. Luckily you can guess there positions most times & as they are crewed weapons tend not to be happy campers when arty hits them.
If people are abusing add a house rule realistic numbers, depending on formation/nation thats a max of 1-3 per company in most cases. Thats singles if you want doubles then buy so number of MGs is correct. Cheaper than 2 singles but less flexible & easier to spot & hit.