A Comparison of SCHV Cartridges

The most important aspect of a rifle/caliber combination is how easy it is to hit a target with it. For the cartridge alone, this depends on five factors: Recoil impulse, bullet drop, bullet drift due to wind, time of flight, and the precision with which the cartridge was made. Because military cartridges are usually held to tighter tolerances than most soldiers will be able to take advantage of, in this article we will only take a look at the first four.

Small-caliber, high velocity cartridges are primarily designed to maximize these four characteristics at ranges below five hundred meters. The following analysis is done on six different SCHV cartridges, five which are or have been in service with a major military, and the sixth being an experimental cartridge. For comparison, I will include one intermediate-caliber, medium velocity cartridge, one full-caliber, low velocity cartridge, and the .30 Carbine.

We will examine the recoil impulse of each cartridge, as wells as the drop, drift, and time of flight of each cartridge at 100, 300, and 500m. We will use figures for each cartridge when shot from a 16" barrel, except the 5.56 FABRL, for which the barrel length is unknown to me. Used in this analysis will be kwk.us's recoil calculator, and JBM's ballistic calculator.

The parameters used in the ballistic calculator are as follows:

Zero Range: 1.0m
Distance to Chronograph: 10.0 ft
Sight Height: 0.00 in Sight Offset: 0.00 in
Zero Height: 0.00 in Zero Offset: 0.00 in
Windage: 0.000 MOA Elevation: 0.000 MOA
Line Of Sight Angle: 0.0 deg Cant Angle: 0.0 deg
Wind Speed: 10.0 mph Wind Angle: 90.0 deg
Target Speed: 10.0 mph Target Angle: 90.0 deg
Target Height: 12.0 in
Temperature: 59.0 °F Pressure: 29.92 in Hg
Humidity: 0 % Altitude: 0.0 ft
Vital Zone Radius: 5.0 in
Std. Atmosphere at Altitude: No Pressure is Corrected: Yes
Zero at Max. Point Blank Range: No Target Relative Drops: Yes
Mark Sound Barrier Crossing: Yes Include Extra Rows: No
Column 1 Units: 1.00 cm Column 2 Units: 1.00 MOA
Round Output to Whole Numbers: No

Let's begin.

5.56x45 M193

Caliber: 5.7 mm
Projectile Weight: 3.56 g
Muzzle Velocity (16" barrel): 960 m/s
Ballistic Coefficient (G7): 0.120
Powder Charge: 1.75 g
Recoil Impulse: 5.96 kg-m/s
Drop 100m: -5.8 cm
Drop 300m: -66.1 cm
Drop 500m: -244.0 cm
Drift 100m: 3.6 cm
Drift 300m: 38.3 cm
Drift 500m: 129.5 cm
Time to 100m: 0.112 s
Time to 300m: 0.397 s
Time to 500m: 0.808 s

5.56x45 M855

Caliber: 5.7 mm
Projectile Weight: 4.00 g
Muzzle Velocity (16" barrel): 900 m/s
Ballistic Coefficient (G7): 0.151
Powder Charge: 1.75 g
Recoil Impulse: 6.14 kg-m/s
Drop 100m: -6.5 cm
Drop 300m: -70.5 cm
Drop 500m: -242.7 cm
Drift 100m: 3.1 cm
Drift 300m: 32.0 cm
Drift 500m: 103.2 cm
Time to 100m: 0.118 s
Time to 300m: 0.404 s
Time to 500m: 0.784 s

5.45x39 7N6

Caliber: 5.6 mm
Projectile Weight: 3.43 g
Muzzle Velocity (16" barrel): 960 m/s
Ballistic Coefficient (G7): 0.168
Powder Charge: 1.40 g
Recoil Impulse: 5.32 kg-m/s
Drop 100m: -5.7 cm
Drop 300m: -59.7 cm
Drop 500m: -198.4 cm
Drift 100m: 2.5 cm
Drift 300m: 25.4 cm
Drift 500m: 80.2 cm
Time to 100m: 0.109 s
Time to 300m: 0.368 s
Time to 500m: 0.699 s

5.45x39 7N22

Caliber: 5.6 mm
Projectile Weight: 3.68 g
Muzzle Velocity (16" barrel): 960 m/s
Ballistic Coefficient (G7): 0.180
Powder Charge: 1.50 g
Recoil Impulse: 5.71 kg-m/s
Drop 100m: -5.6 cm
Drop 300m: -58.8 cm
Drop 500m: -192.3 cm
Drift 100m: 2.3 cm
Drift 300m: 23.5 cm
Drift 500m: 73.2 cm
Time to 100m: 0.109 s
Time to 300m: 0.364 s
Time to 500m: 0.683 s

5.8x42 DBP-10

Caliber: 6.0 mm
Projectile Weight: 4.60 g
Muzzle Velocity (16" barrel): 915 m/s
Ballistic Coefficient (G7): 0.191
Powder Charge (estimated): 1.85 g
Recoil Impulse: 6.89 kg-m/s
Drop 100m: -6.2 cm
Drop 300m: -64.2 cm
Drop 500m: -208.6 cm
Drift 100m: 2.4 cm
Drift 300m: 23.7 cm
Drift 500m: 73.3 cm
Time to 100m: 0.114 s
Time to 300m: 0.380 s
Time to 500m: 0.709 s

5.56x38 FABRL AR-2

Caliber: 5.7 mm
Projectile Weight: 2.40 g
Muzzle Velocity (unknown barrel length): 1,180 m/s
Ballistic Coefficient (G7): 0.126
Powder Charge (estimated): 1.30 g
Recoil Impulse: 4.72 kg-m/s
Drop 100m: -3.8 cm
Drop 300m: -41.2 cm
Drop 500m: -144.0 cm
Drift 100m: 2.4 cm
Drift 300m: 25.2 cm
Drift 500m: 82.9 cm
Time to 100m: 0.090 s
Time to 300m: 0.310 s
Time to 500m: 0.608 s

6.8x43 SPC 115gr FMJ

Caliber: 7.0 mm
Projectile Weight: 7.45 g
Muzzle Velocity (16" barrel): 780 m/s
Ballistic Coefficient (G7): 0.167
Powder Charge: 1.90 g
Recoil Impulse: 8.57 kg-m/s
Drop 100m: -8.7 cm
Drop 300m: -92.9 cm
Drop 500m: -316.9 cm
Drift 100m: 3.5 cm
Drift 300m: 35.4 cm
Drift 500m: 113.7 cm
Time to 100m: 0.136 s
Time to 300m: 0.462 s
Time to 500m: 0.893 s

7.62x39 M43

Caliber: 7.9 mm
Projectile Weight: 8.00 g
Muzzle Velocity (16" barrel): 720 m/s
Ballistic Coefficient (G7): 0.156
Powder Charge: 1.90 g
Recoil Impulse: 8.52 kg-m/s
Drop 100m: -10.2 cm
Drop 300m: -112.1 cm
Drop 500m: -395.9 cm
Drift 100m: 4.2 cm
Drift 300m: 43.4 cm
Drift 500m: 143.4 cm
Time to 100m: 0.148 s
Time to 300m: 0.512 s
Time to 500m: 1.012 s

.30 Carbine Ball M1

Caliber: 7.8 mm
Projectile Weight: 7.13 g
Muzzle Velocity (16" barrel): 580 m/s
Ballistic Coefficient (G1): 0.178
Powder Charge: 0.88 g
Recoil Impulse: 5.41 kg-m/s
Drop 100m: -16.9 cm
Drop 300m: -224.0 cm
Drop 500m: -852.4 cm
Drift 100m: 10.3 cm
Drift 300m: 105.2 cm
Drift 500m: 280.3 cm
Time to 100m: 0.194 s
Time to 300m: 0.749 s
Time to 500m: 1.484 s