on a recent hunt on a closed air force base in my town i dug up 3 spent pistol shell casings( i assume they are pistol), they are 7/8" long and aabout 7/16' wide. the markings on the bottom are F and A, with the number 28 on two of them and 29 on the other one. just curious because in the same area i pulled out a ww1 enlisted mans collar clasp...crossed rifles and the company letter below the rifles. cant find a good site to look for these spent shells....anyone an expert on possible military shells that could point me in the right direction...thanks....mark43