Author Topic: Greenhill Formula Calculator  (Read 5739 times)

John Boy

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Re: Greenhill Formula Calculator
« Reply #1 on: April 02, 2008, 12:27:44 PM »
Sir Charles ... The formula constant is T=150(d/r) for velocities from about 1500 to 2800 fps. Substitute 180 for the 150 value for velocities exceeding 2800 fps.
And for velocities below 1500 fps, substitute 125 for the T constant

According to Hatcher, the bullet used to derive the constant was a Krag 220 grain, L=1.35in., v=2000ft/sec, d=10.9 gm/ml, p=1.221gm/l For i=.61, the constant comes out to 150.
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