Useful Info
I thought some people might find this interesting
Useful info
Some useful values:
1 grain = 0.037 dram
1 pound = 7000 grains
1 pound = 16 ounces
1 ounce = 437.5 grains
1 ounce = 16 drams
1 dram = 27.344 grains
Density of lead is 11.34 gram/cc
1 gram =15.4324 grains
1 inch = 2.54 centimeters
1 meter = 39.37 inches, 3.28 feet and 1.09 yards
pi = 3.14159
Volume of a sphere = 4/3pi R3 (4/3 x pi x radius of sphere cubed)
Radius of a sphere = cube root of (3Volume/4 pi)
Volume x density = weight
To find Twist needed for a bullet
150 x diameter squared divided by bullet length = required spin
Example for a .45 caliber bullet .60 inches long:
150 x .45 x .45 divided by .60 = 50.6 inches
So, for the example bullet, a spin rate of 1:50.6 or faster is required