I bought a Colt's Police Positive .38 Colt New Police revolver and got a box of old ammo with it. There was 21 rounds left in the box that was dated 1940. These cartridges were balloon head and in excellent condition. Since the box was not complete with all rounds, I fired the 21 rounds. They all fired and shot very well. Notice the tips of the bullets are flat nosed. Colt did this so people could buy rounds that were not marked .38 S&W, although the cartridges are interchangeable. I will post a photo of the revolver and the box. The photo of the young lady shooting her Police Positive .38 NP is a friend of mine. Her revolver is a 4" and mine a 6". Hers was made in 1912 and mine in 1913. It was the standard police handgun in the early 1900's.