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AR-15Bolt face: 5.56/.223

5.56x45mm NATO Ballistics

The 5.56x45mm NATO is the standard military cartridge for the M16 and M4 platforms. It runs at higher pressure than .223 Remington and is not recommended to be fired in rifles chambered exclusively for .223. Versatile, affordable, and the default AR-15 chambering.

Cartridge Specifications

SAAMI Max Pressure
62,000 psi
Bullet Diameter
0.224 in
Case Length
1.76 in
Overall Length
2.26 in
Parent Case
.223 Remington
Bolt Face
5.56/.223
Min Barrel
10.5 in
Platform
AR-15

Common Bullet Weights and Types

FMJ 55 grFMJBT 62 grOTM 77 grSP 64 gr

Muzzle Velocity by Barrel Length

Muzzle Energy by Barrel Length

Bullet Drop Table

Values in inches. 16-inch barrel reference data. Positive values rise above line of sight, negative values fall below.

LoadZero100 yd200 yd300 yd400 yd500 yd
55 gr FMJ200 yd1.40-7.1-20.9-42.9
62 gr FMJBT200 yd1.50-7-20.2-40.7
77 gr OTM200 yd1.80-8-22.8-45.4

Wind Drift at 10 mph Crosswind

Drift in inches at a 90 degree full value wind. Estimated from muzzle velocity and G1 ballistic coefficient.

Load100 yd200 yd300 yd400 yd500 yd
55 gr FMJ6.613.219.726.332.9
62 gr FMJBT5.811.617.523.329.1
77 gr OTM5.410.716.121.526.8

Effective Range by Application

Self-defense0 to 200 yd
Varmint hunting0 to 400 yd
Competition0 to 600 yd

Barrel Twist Rate Recommendations

40 to 55 gr1:9 or 1:12
55 to 69 gr1:8 or 1:9
69 to 77 gr1:7 or 1:8
77 gr and heavier1:7

Published Load Data

WeightTypeBarrelMV (fps)ME (ft-lb)BC (G1)Source
55 grFMJ16 in3,1001,1730.243Federal XM193 published load data, 20" test barrel scaled; Hornady ballistic calculator
55 grFMJ18 in3,1801,2350.243Federal XM193 published load data; Hornady ballistic calculator
55 grFMJ20 in3,2401,2820.243Federal XM193 published specification 3240 fps 20" barrel
62 grFMJBT16 in2,9701,2140.307Federal XM855 published load data; ballistic calculator
62 grFMJBT18 in3,0201,2560.307Federal XM855 published load data; ballistic calculator
62 grFMJBT20 in3,0601,2890.307Federal XM855 published specification 3060 fps 20" barrel
77 grOTM16 in2,6801,2280.372Black Hills MK262 Mod 1 published load data; Sierra MatchKing BC
77 grOTM18 in2,7501,2930.372Black Hills MK262 Mod 1 published load data
77 grOTM20 in2,7901,3310.372Black Hills MK262 Mod 1 published specification

Data Disclaimer

Ballistic data is approximate and varies by ammunition lot, barrel condition, altitude, and temperature. Data sourced from Federal XM193 published load data, 20" test barrel scaled; Hornady ballistic calculator; Federal XM193 published load data; Hornady ballistic calculator; Federal XM193 published specification 3240 fps 20" barrel. Always confirm zero and trajectory with your specific firearm.

Pick the right barrel

Twist rate should match the bullet weights you plan to shoot. See barrel steel grades, profiles, chamber types, and twist rate guidance on the barrel specs page, then jump into the builder to filter barrels chambered in 5.56x45mm NATO.