280PLUS
Member
Got the latest American Rifleman today and in it is the formula for figuring ft/lbs of force for a given projectile weight and fps. Thought I'd go ahead and post it and figure the Ft/lbs on one of those 5"/54's we was talkin about a while back
here goes...
KE = (W x V squared) /450,400
Where
KE=Kinetic Energy (ft/lbs)
W= weight of bullet (grains)
V= Velocity (fps)
so that gives us:
72 lbs x 7000 = 504000 gr
so...
KE = (504,000gr x 2600 fps sqd) / 450,400
KE = (504,000 x 6,760,000) / 450,400
KE =3407040000000 / 450400
KE = 7,564,476.02 ft/lbs
imagine that,,,now thats a wallop
and whats a .357?
hmmm...
KE = (158 gr x 1300fps sqd) / 450,400
KE = (158 x 1,690,000) / 450,400
KE = 267,020,000 / 450,400
592.85 ft/lbs
this works...
one more...
KE = (85 gr x 1o00 fps sqd) / 450,400
KE = (85 x 1,000,000) / 450,400
KE = 850,000,000 / 450,400
KE = 188.72
it works!! it works!!
oh well, thought it might be of interest or use to some of us
m
here goes...
KE = (W x V squared) /450,400
Where
KE=Kinetic Energy (ft/lbs)
W= weight of bullet (grains)
V= Velocity (fps)
so that gives us:
72 lbs x 7000 = 504000 gr
so...
KE = (504,000gr x 2600 fps sqd) / 450,400
KE = (504,000 x 6,760,000) / 450,400
KE =3407040000000 / 450400
KE = 7,564,476.02 ft/lbs
imagine that,,,now thats a wallop
and whats a .357?
hmmm...
KE = (158 gr x 1300fps sqd) / 450,400
KE = (158 x 1,690,000) / 450,400
KE = 267,020,000 / 450,400
592.85 ft/lbs
this works...
one more...
KE = (85 gr x 1o00 fps sqd) / 450,400
KE = (85 x 1,000,000) / 450,400
KE = 850,000,000 / 450,400
KE = 188.72
it works!! it works!!
oh well, thought it might be of interest or use to some of us
m
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