Use these formulas to help you make ballistic decisions about the guns you use or want to compare.
Some believe that a good way to compare the terminal performance of various cartridges and loads is by crush cavity. The crush cavity is simply the size of the hole a bullet makes as determined by its upset diameter and by the depth it penetrated. Simply put, the crush cavity is the volume in cubic inches of the hole a bullet makes inside something. This formula is best used when testing ammunition in ordnance gelatin, Clear Ballistics, or similar mediums. To use this calculator, enter the diameter of a recovered bullet (in inches) and the depth the bullet penetrated (in inches)
Professional fighters are often talked about in terms of how they rank, pound for pound. I felt this same ranking could be applied to rifles to help us evaluate how accurate/precise they are in relation to how much they weigh. Often, it’s the heavy rifles that shoot the best, but how does a light rifle that shoots very well compare to a heavy rifle. This formula allows that comparison and scores the precision of a rifle based on how much it weighs. Just enter the weight of the rifle – with or without accessories – in pounds, and then enter a single group size or an average group size at 100 yards. The result will give the rifle an accuracy by pound for pound score from 0 to 100, with 100 being perfect.
The kinetic energy a bullet has is provided by most ammunition manufacturers. However, these figures are based on factory – estimated – velocities. With this formula you can determine the kinetic energy of any bullet, at any distance, as long as you know the bullet’s weight and velocity at that distance. Just enter the bullet’s weight (in grains) and its velocity in (fps)
Though the calculation of recoil energy and velocity is a mathematical equation, there are some variations on the equation. And too, it is impossible to “calculate” the actual felt recoil due to the differences in stocks and grips, and in humans. However, this calculator will allow you to make a reasonable comparison with regard to how hard different firearms will recoil. Ultimately, your perception of recoil is more important.