Posted: 5/15/2010 6:11:03 PM EDT
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EK 4-1945 3 in MK-7 50 cal Lot 113 WEM (anchor symbol) It is 23" tall. Traded my brass traps and valves for it at the scrapper. Anchor surely means Navy but what gun and typical use? Why 50 cal when it is a 3" projectile? |
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Its from a 3"/50 gun. Common in use on a lot of ships up until the 1990's or so. The 3"/50 uses a fixed cartridge (like a rifle cartridge) rather than separate loading.
In this case, caliber indicates the length of the gun barrel. In this case the barrel is 50 times the bore diameter in length, or, 150 inches. |
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Quoted: Why is the barrel length important? Different charges/shells for different barrel lengths with the same diameter?Its from a 3"/50 gun. Common in use on a lot of ships up until the 1990's or so. The 3"/50 uses a fixed cartridge (like a rifle cartridge) rather than separate loading. In this case, caliber indicates the length of the gun barrel. In this case the barrel is 50 times the bore diameter in length, or, 150 inches. |
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Just the way the navy does it, I think. Most naval guns (US Navy guns, anyway) are described like that
3" 50 cal is a sort of between 5 inch DP and 40 mm. Generally phased out by the mid-late 70's. The radar targeted 3" mounts died about that time. Cool brass though 
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Quoted:
Just the way the navy does it, I think. Most naval guns (US Navy guns, anyway) are described like that 3" 50 cal is a sort of between 5 inch DP and 40 mm. Generally phased out by the mid-late 70's. The radar targeted 3" mounts died about that time. Cool brass though Army mucks around with the designator as well. For example, the M256 cannon on the M1A1 tank is a 120mm/L44, 44 calibres long. The lengthened version found on Leopards is the 120mm/L55, it's got an extra meter and a bit on it. So far, all L55 ammo can be used in L44 guns. I am unaware of any chamber pressure limit differences. A related problem was in WWII, the difference between the 3" gun as used by tank destroyer units, and the 76mm gun as used by tank units. 3" is, of course, 76mm, give or take a micron. But though the projectiles were the same, the casings were not, so one was named in metric, the other in inches, in order to differentiate the two. NTM |