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Old 10-02-2012, 22:08   #8
Counting Beans
Join Date: Dec 2008
Location: Boise, Idaho
Posts: 3,185
Originally Posted by awdxtc View Post
Why does the list show the underwood 155gn tmj at over 800lbs of energy?
Energy is a calculated value derived from the measured velocity and bullet weight.

The calculation for engergy is:

velocity (FPS) squared times the bullet weight (grains). Divide that value by a constant that is roughly 450,400.

Data from drsjr1969 input into the equation gives:

(1551*1551*155)/450400 => 828 lb/ft.

Lots o' energy in that load!

As a side note, the highest energy I have personally chronographed through my G20 is 889 lb/ft with a handloaded Nosler 135 gr JHP. That was a scorcher!
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