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37 MM rounds for review

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    37 MM rounds for review

    Can anyone tell me about these two rounds. The larger shell is marked 37mm M2. The small 37mm. I cant find any rounds these sizes when I do a search they all are much larger.
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        You did not specify the dimensions of the cartridge cases !!!................. The length and diameter of the rim are required.


          small shell is 3 3/8 inches long and Rim DIA is 1 3/4 inch
          Large shell is 5 1/2 inches long and Rim DIA is 1 3/4 inch


            As I see it.... it is these rounds with slightly shortened cartridges :
            the American Armament Corporation was a controversial organisation which attracted a lot of publicity (not all of it good) in the 1930s. They proposed a wide range of different guns and ammunition for various roles, including aircraft and AFV armament, all in 37 mm calibre. None of these was adopted by the USA or any other major army, but a few of them saw service in obscure corners of the world.

            37 x 87R rim dia 44,4mm (Type M aircraft)The 37 x 87R was used in an automatic gun which was the first model to emerge, being tested in 1934 (the company was only founded in 1933). The gun was known as the Type M as an aircraft gun (in a turret), and on a wheeled mounting was known as the Automatic or Mountain Infantry Gun


            37 x 142R (M2) rim dia 44,4mm ( Rapid Fire Field Gun )



              With that info I was able to find this -

              AAC made four different 37 mm cartridges, as follows. They are instantly recognisable because the company (not one to miss any marketing opportunity) ensured that its full name was boldly stamped on the base of each cartridge case.

              37 x 87R: rim diameter 43.9 mm; body diameter 39.6 mm (this was basically a slightly shortened version of the universal 37 x 94R Hotchkiss).
              Weight of round 635 g, propellant 24.3 g, projectile 500 g (1.1 lb), fired at a muzzle velocity of 380 m/s (1,250 fps). The chamber pressure was only 90 MPa (13,000 psi).

              37 x 142R: rim diameter 44.7 mm; body diameter 40.5 mm (this was basically a slightly lengthened version of the USN 37 x 136R "Heavy One Pounder" case).
              Weight of projectile (HE, AP and Canister) 570 g (1.26 lb), fired at a muzzle velocity of 610 m/s (2,000 fps). Also, Super AP loading, 660 g (1.46 lb) at 565 m/s (1,850 fps), said to penetrate 25 mm hardened steel "at all battle ranges and at a considerable angle of impact".

              37 x 178R: rim diameter 54.2 mm; body diameter 50.0 mm (this seems to have been based on one of the larger Browning cases).

              37 x 203R: rim diameter 54.2 mm; body diameter 50.0 mm (a longer version of the above).
              Weight of round 780 g, propellant 150 g, projectile 500 g (1.1 lb), fired at a muzzle velocity of 610 m/s (2,000 fps) from an L/40 barrel or 820 m/s (2,700 fps) from an L/50 barrel*.


                Thank you for clarifying the details..............


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