14 Factors Affecting Velocity

Velocity Trends

Initial rounds show regular patterns, not predictable, minimized by clean tubes

Ammunition Lots

Variations in projectile and propellant lots affect mean velocity

Tolerances in New Weapons

Variations in chamber and bore dimensions cause ±4 m/s differences

Tube Wear

Reduces MV with increased firing

Non-Uniform Ramming

Affects chamber volume and gas sealing, causing dispersion

Rotating Bands

Improper seating increases wear and dispersion

Propellant and Projectile Temperatures

Higher temperatures increase burning rate and MV

Moisture Content

Affects burning rate, requiring proper storage

Propellant Position

Improper placement reduces MV

Projectile Weight

Heavier projectiles reduce MV; correction factors in Table F

Coppering

Friction deposits copper, affecting MV

Propellant Residue

Accelerates tube wear

Tube Conditioning

Temperature affects resistance and dispersion

Tube Memory

Tube reacts consistently to firing stress

Tube Jump

Causes tube displacement at firing