Even the Beretta M9 9mm pistol, standard side arm of the US Army, has an effective firing range of 50m, or 89cm = 35" in 1/56th.
For Fulda Gap I chose this rule:
Even with the abstractions of time and distance in a wargame, modern weapons have ranges exceeding the usual size of a gaming table by far.Therefore, all weapons have a theoretical unlimited range only restricted by Line-of-Sight. The ranges given for each weapon type indicate an optimal fighting distance. Up to this distance, shooting does not suffer penalties. If the target is further away, a -1 penalty applies for every time the optimal distance is exceeded. For example, a soldier with an Assault Rifle fires at an enemy squad 50" away. He suffers a penalty of -2, -1 for exceeding 24" and -1 for exceeding 48” (2x24").Just for comparison: even under best conditions, a soldier won't be able to hit an enemy with an Assault Rifle at a distance of 97", roughly translating into 200 meters, while the official effective firing range for a real-life M16 at a point target is 550 meters.
This changes the dynamic of the game quite a bit - you can't stay out of range, you must stay out of sight.
It also allows to streamline more rules - for example, all anti-tank guns can use the same range (48") and will only differ in their PEN-value.
In reality, it allows to engage the enemy earlier in the game, but will even out during later turns. Cover, pin marker and other modifiers will limit effective firing ranges fast - a unit with two pin markers shooting at an enemy in soft cover is already down to an effective range of 24".