2018
Carey Alvarez Bacha
Charleston, WV
This presentation will outline the validation of the IMADA DS2-44 digital force gauge. The validation study included ten firearms laboratory personnel conducting ten force gauge measurements on fourteen firearms/actions. This data was used to calculate the minimum force, maximum force, mean force, standard deviation, and coefficient of variation (%CV) for each firearm/action. The single action rifle, single action shotgun, single action pistol, double action pistol, single action revolver, and double action revolver, with the largest %CV were determined from this data and referred to as worst case scenario firearms/actions. The results from the validation study showed significant differences between study participants in mean force gauge readings for each firearm. Potential factors contributing to the variation in force gauge readings between study participants will be addressed. Three additional firearms laboratory personnel then conducted ten force gauge measurements on the six worst case scenario firearms/actions. The combined data from all thirteen firearm laboratory personnel was used to calculate the trigger pull uncertainty of measurement for the main firearm types/actions, including single action rifle, single action shotgun, single action pistol, double action pistol, single action revolver, and double action revolver. This presentation will address the advantages and disadvantages of the method utilized by the HCIFS FIL to calculate and report trigger pull uncertainty of measurement, as compared to alternative methods.