Measuring felt recoil of sporting arms

For competitors in the shooting sports, gun recoil can affect performance and create discomfort. An objective method of measuring felt recoil forces would be useful to evaluate methods of recoil reduction. An experimental test apparatus was developed to measure recoil forces of sporting rifles and shotguns. No modifications to the firearms themselves were necessary to make the measurements. Through both inertial and dissipative restraint mechanisms, the apparatus reproduced gun movement that was representative of that experienced by a particular shooter. This should result in measured recoil forces similar to those experienced by the shooter. The apparatus measures the horizontal shoulder force and the vertical force component exerted at the stock comb. The recoil event was found to be quite short, having duration on the order of 10 ms. Peak recoil forces for common shotgun target loads were in the range of 1.6–2.2 kN (360–494 lbf). The apparatus was found sensitive enough to measure recoil force differences among different factory loaded ammunition, and differences in recoil force imparted by different firearms shooting the same ammunition. The apparatus should prove useful for quantifying differences in felt recoil as affected by ammunition type, gunstock geometry, barrel porting, recoil reduction devices, and gun weight, among other factors.