Descriptive InformationHarpers Ferry experimantal rifle, Model 1803-1814, .48 caliber close-up of gun, 3.5x3.5 negative filed. Original caption: NHF 12, Harper House Porch from Stone Steps before Porch Removal, Jan 1955. NHF-1518, Harper's Ferry Experimental Rifle, Model 1805-14, 48 Caliber - Close-up of gun, 3 1/2 x 3 1/2 Negative Filed.