Fig. 1From: Divergent gunshot residues and characterization of the memory effect in a .22 caliber revolver and pistolThe Smith and Wesson Model 18 revolver with the attached vellum backed by masking tape draped over its side to intercept cylinder gap GSR, minimizing retrograde muzzle GSR contamination. The exit port of the Ruger MKII pistol was similarly draped for breech GSR collectionBack to article page