Light Spear (equivalent to a javelin): 2 pounds, 50 mph, 1" diameter
Heavy Spear (equivalent to a Roman pilum): 5 pounds, 25 mph, 1 1/2" diameter
Light Atlatl Dart: 3 ounces, 85 mph, 1/2" diameter
Heavy Atlatl Dart: 6 ounces, 70 mph, 5/8" diameter
Kinetic Energy Hunting Usage
< 25 ft. lbs. Small game
25 - 41 ft. lbs. Medium Game (deer, antelope, etc.)
42 - 65 ft. lbs. Large Game (elk, black bear, wild boar, etc.)
> 66 ft. lbs. Toughest Game (cape buffalo, grizzly, etc.)
MOMENTUM CALCULATIONS:
In descending order
Projectile Weight Velocity Momentum
Heavy Spear 5 pounds 37 fps 5.75 slug-feet/second
Light Spear 2 pounds 73.5 4.57
Heavy Dart 6 ounces 103 1.20
Light Dart 3 ounces 125 .73
SECTIONAL DENSITY CALCULATIONS:
In descending order
Projectile Weight Diameter Sectional Density
Heavy Spear 5 pounds 1.5" 2.222 psi
Light Spear 2 pounds 1" 2.000
Heavy Dart 6 ounces .625" .960
Light Dart 3 ounces .5" .750
How Hard Does It Hit?
www.thudscave.com/npaa/articles/howhard.htm -