RESUMEN
Objective To provide a mathematical formula and method for estimating the distance of shooting by uniform shotgun. Method 360 distribution graphs of canister were made on experimental target paper by shooting with No. 12 and No. 16 uniform shotgun (made in China), using No. 1 and No.3 pellets at the distance of shooting from 1m to 12m. The data of graph measuring and experimental distance were analyzed by mathematic theory. Results Six different types of mathematic formula were obtained for deduce the distance of shooting. They are: 12-1 type (choke) ss= -0.2 + 0.44d; 12- 1 type (no choke) ss= -0.94 + 0.63d; 12-3 type (choke) ss= -0.59 + 0.52d; 12-3 type (no choke) ss= -0.36 + 0.34d; 16-1 types= -0.37 + 0.30d; 16-3types= -0.16 + 0.23d. General software was made using Visual Basic 5.0 computer program. Conclusion This method can be used to deduce the distance of uniform shotgun shooting with little error.