Original Item: Only One Available. This is incredibly rare! A genuine January 1945 produced Mark 9 USN depth charge. The only other examples we've seen are in museums. This example is BATF compliant and totally inert. This example still bears its original brass data plate that reads:

DEPTH CHARGE CASE
MK-9 MOD-3
INSP. (ANCHOR) JFS
BEATRICE STEEL TANK MFG. CO.
BEATRICE, NEBRASKA
DATE OF MFG
1-2-45

During World War II, the USA built a total of 622,128 depth charges of all types between December 1941 and September 1945. This figure does not include Hedgehog, Mousetrap and experimental units not placed in service use. Over half of these depth charges were still on hand at the end of hostilities.

In the first few months of the war only 5 percent of all depth charge attacks were successful. Normal combat conditions reduced that figure to 3 percent. Combat records showed that in early 1942 the lethal probability of a single depth charge pattern (barrage) was about 3 percent and five attacks would raise the chance of a kill to about 10 percent. The possibility of inflicting significant damage to a submarine was about 30 percent after five attacks. By the end of 1943, better weapons and tactics had improved these figures such that about 30 percent of all detected submarines suffered at least some damage and 20 percent were killed. By the last year of the war, at least 35 percent of all submarines attacked were being damaged while 30 percent were killed. In mid-1944, the USN was claiming an 8 percent kill rate with a single Hedgehog pattern. By the middle of 1945, that figure had risen to 10 percent.

In the Atlantic Theater, US surface ships sank 60 submarines, shore-based aircraft sank 54, ship-borne aircraft sank 32 and 40 were destroyed by bombing raids on yards and bases. In the Pacific Theater, surface ships sank 60 Japanese submarines, shore-based aircraft sank 3.5 and ship-borne aircraft sank another 9.5.

The United States WW2 Mk 9 depth charge was designed in 1941 and issued in 1943, it was streamlined and equipped with fins to impart rotation, allowing it to fall in a straight trajectory with less chance of drifting off target. This depth charge contained 200 pounds (91 kg) of Torpex. This DC had a "teardrop" shape for a much greater sink rate and was the standard DC by the latter part of the war. In some later versions the depth limit was increased to 1,000 feet (305 m).

Date of Design: 1941
Date In Service: 1943
Dimensions: 27.5" High, 17.5" diameter
Empty weight: 120 Lbs
Explosive Charge: 200 lbs. (91 kg) Torpex
Sink Rate / Terminal Velocity: 22.7 fps (6.9 mps)
Settings: 50 - 300 feet (15 - 91 m) or 600 feet (183 m)

The technical manual for the Mk9 depth charge can be found at this link.

In one of the photos we listed you'll see multiple Mark 9 Depth Charges on USS Inch DE-146 on 12 June 1944. Note the K-guns located adjacent to the racks and the arbors stored under the racks. This arrangement allowed quicker reload times, as once the arbors were loaded into the K-guns, the DCs simply had to be pushed sideways out of the rack and onto the arbors. On 11 June 1944, USS Inch together with sister-ships USS Frost DE-144 and USS Huse DE-145 attacked and sank the German U490 and then rescued her entire crew of 80 sailors. In the photograph above, three of these prisoners (center, two wearing life vests, one in shirtsleeves) can be seen. Note the guard with the Thompson sub-machine gun at right. U.S. Naval Historical Center Photograph # NH 80-G-270265.