G1 Drag Standard
Definition
The Gavre Commission reference projectile: flat base, round-nose ogive. Established in the late 19th century and codified at Aberdeen Proving Ground. Standard for most civilian and law enforcement ammunition catalogues globally.
- Origin
- Gavre Commission, late 19th century
- Shape
- Flat base, round-nose ogive
- Codified at
- Aberdeen Proving Ground
- Usage
- Standard for most civilian and law enforcement ammunition
Common questions
Why does most ammunition still use the G1 standard instead of G7?+
G1 predates modern bullet shapes and was fitted to older flat-base, round-nose projectiles, but manufacturers kept publishing ballistic coefficients on the G1 scale for consistency and comparability across their catalogues even for bullets whose shape no longer matches the G1 form.
What error results from applying a G1 ballistic coefficient to a boat-tailed spitzer bullet?+
Because the G1 reference shape drags differently than a modern long, boat-tailed bullet, a G1-based ballistic coefficient predicts trajectory less accurately at longer ranges, which is why precision shooters increasingly prefer G7-referenced coefficients for that bullet class.
Related terms
- Aerodynamic Drag
- The retarding force exerted by air on a moving projectile. Proportional to air density, the square of velocity, the drag coefficient, and...
- Ballistic Coefficient (BC)
- The ratio of a projectile's sectional density to its drag relative to a reference standard (G1 or G7). Higher BC means less...
- Drag Coefficient (C_D)
- A dimensionless number characterising the aerodynamic drag force relative to the dynamic pressure and the projectile's cross-sectional area. Varies with Mach number;...
- G7 Drag Standard
- A long, boat-tailed secant-ogive reference projectile developed by Bryan Litz at Applied Ballistics. More accurate for modern spitzer-BT precision and military rifle...
- Hatcher Rule
- A simplified wind-drift estimation formula from Major General Julian Hatcher's Hatcher's Notebook (1947). Useful as a field check and courtroom cross-reference; diverges...
- Litz Wind Drift Model
- The velocity-integrated wind-drift calculation method from Brian Litz's Applied Ballistics for Long Range Shooting (2015), implemented in AB Quantum and Hornady 4DOF....
- Sectional Density
- A bullet's mass divided by the square of its diameter (in consistent units). A component of BC; higher sectional density generally produces...
- Transonic Regime
- The velocity range from approximately Mach 0.8 to 1.2 (272 to 408 m/s at sea level, 15 degrees C). Wave drag peaks...
- Wind Drift
- Lateral deflection of a bullet by a crosswind component. Grows with time-of-flight (faster than range) and is the most variable error source...