Ballistics information for m855 ammunition
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Executive summary
M855 is a 62‑grain 5.56×45mm NATO ball cartridge widely used since the early 1980s; published technical sources list muzzle velocities around 2,970–3,150 ft/s for related variants and a G7 ballistic coefficient near 0.151 (SS109/M855) while measured G1/G7 BC values reported by users and testing vary substantially (examples: G1 ≈0.300, G7 ≈0.151) [1] [2] [3]. Aerodynamic and yaw behavior—particularly early yaw and angle‑of‑attack variability—is documented in government testing and can affect terminal performance and accuracy [1] [4].
1. What M855 actually is — design and official role
The M855 (often called “green tip”) is a 62‑grain 5.56×45mm NATO ball cartridge built around a boat‑tailed projectile with a steel penetrator in the tip; it was adopted as a standard NATO/US military loading around 1982 and is specified for rifles like the M16A2 and machine guns such as the M249E1 [5] [6]. Official military data sheets classify it as a general‑purpose ball cartridge intended for use against personnel and unarmored materiel [6].
2. Published velocity and ballistic‑coefficient figures — official vs. field
Reference documentation lists muzzle velocities and ballistic coefficients for the family: comparisons of the SS109/M855 to the newer M855A1 show muzzle velocities on the order of 2,970–3,150 ft/s depending on rifle platform, and a G7 BC for SS109/M855 of 0.151 in military ballistics summaries [1]. Independent and user‑collected chronograph reports show lower and variable muzzle velocities (e.g., around 2,975 fps from a 16" AR) and BCs quoted using the G1 model of roughly 0.300 in forum testing — demonstrating that reported numbers differ by measurement method and model [3] [2].
3. Aerodynamics and in‑flight behavior that matter to shooters
Technical ballistic research documents that M855 exhibits measurable pitch and yaw behaviors at various Mach numbers (figures showing pitch and yaw vs. range for M855 at about Mach 1.47 appear in a government report), and that angle‑of‑attack and fleet yaw variability between rifles and lots can be noticeable, especially at close ranges [4] [1]. The Joint Service Wound Ballistic IPT identified yaw issues that make effect on target range‑dependent; those dynamics influence terminal effects and accuracy [1].
4. Terminal effects and common perceptions — competing viewpoints
Sources and shooter commentary emphasize competing views: manufacturers and military tests describe M855 as having superior penetration (noted penetrator tip) and standardized ballistics [1] [6], while shooters commonly report that M855 can “tumble” at short ranges and may pass through targets at longer ranges with less disruptive energy transfer — leading to the reputation that it “just pokes holes” at distance [5]. Available sources document the yaw/tumble tendency and range dependence but do not provide a single unified assessment of “stopping power”; both the military testing (focused on penetration and trajectory) and user reports (focused on terminal effect) are present in the record [1] [5].
5. Practical ballistics data and calculators — how to get usable numbers
Ballistic calculators and compiled charts (ammo maker compendia, ShootersCalculator) produce trajectory tables, drop, velocity and energy predictions when you supply muzzle velocity and a BC; multiple online charts for 5.56/M855 exist (ammo.com, ShootersCalculator) but they warn results are approximations and advise confirming with chronographing and live zeroing for your specific rifle and environment [7] [8] [9]. Forum threads and range reports show shooters often measure different MVs and BCs and then feed those into calculators to produce usable drop charts [3] [10].
6. Limits of available reporting and what’s not found
Available sources document muzzle velocity ranges, BC estimates, and aerodynamic/yaw testing, but do not provide a single authoritative, universally applicable BC/MV pair for every barrel length or lot; nor do they offer an independent, peer‑reviewed consensus on terminal “stopping power” across all engagement ranges — users must chronograph and confirm zero with their own weapon [1] [3] [2]. Specific manufacturer lot‑to‑lot variances, the full TM‑43 load tables cited in contractor forums, and precise barrel‑length‑by‑lot performance tables are referenced in community threads but not reproduced as a single authoritative dataset in the supplied sources [6] [11].
If you want actionable numbers for shooting: chronograph your M855 lot from your rifle to get true muzzle velocity, choose a BC consistent with the model (G1 vs G7) you intend to use — military summaries show G7 ≈0.151 for SS109/M855 while some G1 field reports show ≈0.300 — then run a trajectory calculator and confirm with live‑fire zeroing [1] [2] [7].