Quote:
Originally Posted by cloverleaf
Interesting post.. for all my inquisitive nature I'd never considered the derivation of the constant. I've unquestioningly used 450240 ever since I first read it in Airgunner ( ) at the age of about 15
Rob; as you point out this issue arises from varying available values for gravitational acceleration; would it not be easiest to work through the SI formula converting to imperial, using the standard gravitational acceleration constant of 9.80665m/s^2..?
As you rightly point out the potential for inaccuracy from such variations is pretty small  at this point I'd start worrying more about the accuracy of my measuring equipment, rounding errors etc

9.80665 = 32.174 which is what I tend to use.
That means you'd be using the constant 450436 in your calculations.
800 fps for an 8.4 pellet would be 11.935fpe
or 11.99fpe for an 8.44grn pellet.