http://www.inetres.com/gp/military/i...g/50_ammo.html
Penetration capabilities of a single .50 caliber M2 AP round fired from a 45-inch barrel.
Range Armor Plate (homogeneous) Armor Plate (face-hardened) Sand Clay
219 yd (200 m) 1.0 in (25.4 mm) 0.9 in (22.9 mm) 14 in (355.6 mm) 28 in (711.2 mm)
656 yd (600 m) 0.7 in (17.8 mm) 0.5 in (12.7 mm) 12 in (304.8 mm) 27 in (685.8 mm)
1,640 yd (1,500 m) 0.3 in (7.6 mm) 0.2 in (5.1 mm) 16 in (406.4 mm) 21 in (533.4 mm)
So at 4 hexes you get 1 inch of pen ( maybe ) and at the equivalent of 13 hexes you would get 1/2 - 3/4 of an inch therefore a 1 would defeat the round in most cases
The M312 and the SLAP's have a 4 penetration
Don