To calculate muzzle energy:

Velocity X Velocity X Bullet Weight  =  ft. lbs.
 450,240            
              
(velocity in feet per second, weight in grs.)
example:  a 115 grain bullet traveling at 1300 fps = 431 ft. lbs. of muzzle energy

* bullet weight should be on ammo box.  If velocity is not on box you may have to visit the manufacture's web site.

   303.734.7124
Potomac Ltd.  /  4  West Dry Creek Circle, Suite 100  /  Littleton, CO  80120
 and
    7350  E. Progress Place, Suite 100  /  Greenwood Village, CO  80111