Mortal bullet has one short deep wide cut upon a "land." All test bullets fired through Sacco's pistol have two long shallow parallel cuts on a different "land." After Hamilton pointed out this wide difference the Prosecution vigorously objected to any more test shots in Sacco's pistol. B-2 V-2 - test bullets fired thru Sacco's pistol during trial. Mortal bullet ex 18 claimed by Prosecution that it was fired thru Sacco's pistol.