I used the following formula to calculate the volume of a cylinder [Dia; squared x 3.142 x L] divided by 4. The.752 diameter used in my pressure calculation was derived from [.775-.729]divided by 2 + .729] =.752 which was an arbitary diameter that I thought would likely approximate the diameter/volume change as the charge transitioned from 12G to 10G whilst traversing the 10G forcing cone.The resultant 6% estimated, drop in pressure is modest.Assuming an intial muzzle velocity of 1200 ft/sec at 6000 psi breech pressure, the resultant drop in muzzle velocity would be 72 ft/secapprox.This minimal reduction in velocity would appear to support user reports that gaugemates function in a satisfactory manner.
Last edited by Roy Hebbes; 10/18/09 08:03 PM.
