Originally Posted by
tinbum
Where 450240 is twice the gravity constant multiplied by grains per lb. (7000)
You can change the constant accordingly if you weight shot in ounces or lbs.
Another interesting number is 671. Any object travelling at 671fps has a ft/lb power the same as its weight in grains. Ie a 15.6gr AA pellet at 671 is running at 15.6 ft/lb. an 8.4gr at 8.4 ft/lb etc.
so a 5lb cannon ball at 671fps is a whopping 35000 ft/lb, but it will still have the same basic trajectory as the .177 8.4gr pellet.
I think the British, as distinct from the American Standard for g results in a divisor of 450436.68 .
The 5lb cannon ball (and who ever used a 5 -pounder? ) won't have the same trajectory as any airgun pellet because there's a helluva lot more grains per square unit of cross section in the 5lb ball, so it'll retain velocity much better. You'd probably start to notice the difference within 50 yards or so.
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