800 meters is the stated maximum effective range for the M80A1 round (7.62×51 NATO). How would the 6.5×50 ICS fair by comparison? Values are from JBM ballistics program, 200 meter zero, drop and windage (10 mph crosswind) are in mils. Muzzle values are for a 16-inch barrel.

The BC and muzzle velocity of the M80A1 are something of a puzzle. In my previous post, I conclude that the G7 BC is about 0.190. The muzzle velocity is stated in published material from the U.S. Army as 3050 fps at 78 feet from a 24.7″ barrel (general machine gun). The JBM program puts that muzzle velocity at 3117. But for comparison purposes, a 16″ barrel would reduce the velocity to about 2900 fps for a 16″ barrel, or 3050 for a 22″ barrel (25 fps difference per inch of barrel length).

107 Sierra Match King with a G7 BC of 0.230 (Litz)

— muzzle —

velocity: 2750 fps

energy: 1805 ft-lbs

— 800 meters —

drop: 7.8 mils

windage: 2.5 mils

velocity: 1275 (Mach 1.14)

energy: 386 ft-lbs

123 Sierra Match King with a G7 BC of 0.260 (Litz)

— muzzle —

velocity: 2600 fps

energy: 1854 ft-lbs

— 800 meters —

drop: 8.1 mils

windage: 2.3 mils

velocity: 1310 (Mach 1.17)

energy: 469 ft-lbs

130 Berger Hybrid OTM with a G7 BC of 0.287 (Litz)

— muzzle —

velocity: 2500 fps

energy: 1811 ft-lbs

— 800 meters —

drop: 8.3 mils

windage: 2.1 mils

velocity: 1340 (Mach 1.2)

energy: 518 ft-lbs

M80A1 EPR from a 22″ barrel

— muzzle —

velocity: 3050 fps

energy: 2700 ft-lbs

— 800 meters —

drop: 7.1 mils

windage: 2.8 mils

velocity: 1221 (Mach 1.094)

energy: 430 ft-lbs

At 800 meters, all three ICS rounds are above transonic (Mach 1.1 or higher), and have higher velocity and less drift than the M80A1 round. Two of the ICS rounds retain more energy, but the M80A1 has less drop than all three. All three ICS rounds offer at least 850 ft-lbs lower muzzle energy, translating into much lower recoil. Moreover, the ICS rounds accomplish this with a much shorter barrel (16″ vs. 22″).