Tony Williams
Well-Known Member
Hello Mark,
I clearly made a mistake in Rapid Fire (not the only one!) concerning the 37x137R cartridge in the 1 1/4 pdr Maxim. I have been working on a revised version of the book with a lot more info about ammo, aided in this case by Bob Mellichamp's excellent books on 37mm ammunition and guns.
This is what I have in the current draft about these cartridges:
37 x 124R Maxim-Nordenfelt Mk III 1¼ Pr "Heavy" and Vickers 1½ Pounder
This ammunition was developed late in the 19[SUP]th[/SUP] Century for the 1¼ Pr Maxim-Nordenfelt Mk III "Heavy" of 1898. This saw little use but the cartridge was adopted in modified form (including a different primer) some years later for the Maxim-based Vickers M1915 1½ Pr, used by the Royal Navy. This also saw little use before being replaced by an evolutionary development, the 40 x 158R 2 Pr Pom-pom during World War 1. The ammunition was also used in the Vickers 1½ Pr Type B semi-automatic aircraft gun.
The ammunition used a rimmed and bottlenecked brass cartridge case wider as well as longer than the 1 Pr. The projectiles initially used in the Vickers copied the Maxim in weighing 1¼ lbs (570 g), but very few of these were made before the shell weight was increased to 1½ lbs (680 g).
Overall round length of the Vickers varied with the projectile but was 210 mm with the APHE shown; weight was around 850-900 g. Both base-fuzed steel-pointed and nose-fuzed explosive projectiles (containing 67.5 g explosive) were used, with a shell weight of 680 g and an MV of 640 m/s from an L/42.5 barrel.
There was another cartridge of this size but using a belted case, so has the designation 37 x 124B. It was developed for the Browning-pattern M1924 semi-automatic gun fitted to some US light tanks in the 1920s, but this remained experimental (although it was the ancestor of the M4 aircraft gun described below). Shell weight was 570 g.
37 x 136R USN 1 Pounder Mk 6, Heavy
This cartridge was originally designed for a manually-loaded Hotchkiss gun which entered USN service in about 1890 and was also used in various other guns and sub-calibre training systems. It was adopted for two automatic weapons in the first few years of the 20[SUP]th[/SUP] century: an enlarged Maxim "Pom-pom" known as the One Pounder Maxim-Nordenfelt, Heavy, Mk 1 (later designated 1 pdr Mk 6), which during World War 1 was ordered in large numbers for the USN; and another US automatic cannon developed by Samuel N McClean (of Lewis Gun fame). Although the gas-operated McClean gun failed to be adopted by the USA, a sale to Russia during World War 1 subsequently led to the guns being widely distributed.
The brass cartridge case was rimmed and slightly bottlenecked. Various projectiles were used, but all seem to have been of the base-fuzed steel pointed type. The overall length of the round was 210 mm and the weight was around 600 g. The standard projectile weight was 476 g and the MV 640 m/s from an L/42.5 barrel.
I clearly made a mistake in Rapid Fire (not the only one!) concerning the 37x137R cartridge in the 1 1/4 pdr Maxim. I have been working on a revised version of the book with a lot more info about ammo, aided in this case by Bob Mellichamp's excellent books on 37mm ammunition and guns.
This is what I have in the current draft about these cartridges:
37 x 124R Maxim-Nordenfelt Mk III 1¼ Pr "Heavy" and Vickers 1½ Pounder
This ammunition was developed late in the 19[SUP]th[/SUP] Century for the 1¼ Pr Maxim-Nordenfelt Mk III "Heavy" of 1898. This saw little use but the cartridge was adopted in modified form (including a different primer) some years later for the Maxim-based Vickers M1915 1½ Pr, used by the Royal Navy. This also saw little use before being replaced by an evolutionary development, the 40 x 158R 2 Pr Pom-pom during World War 1. The ammunition was also used in the Vickers 1½ Pr Type B semi-automatic aircraft gun.
The ammunition used a rimmed and bottlenecked brass cartridge case wider as well as longer than the 1 Pr. The projectiles initially used in the Vickers copied the Maxim in weighing 1¼ lbs (570 g), but very few of these were made before the shell weight was increased to 1½ lbs (680 g).
Overall round length of the Vickers varied with the projectile but was 210 mm with the APHE shown; weight was around 850-900 g. Both base-fuzed steel-pointed and nose-fuzed explosive projectiles (containing 67.5 g explosive) were used, with a shell weight of 680 g and an MV of 640 m/s from an L/42.5 barrel.
There was another cartridge of this size but using a belted case, so has the designation 37 x 124B. It was developed for the Browning-pattern M1924 semi-automatic gun fitted to some US light tanks in the 1920s, but this remained experimental (although it was the ancestor of the M4 aircraft gun described below). Shell weight was 570 g.
37 x 136R USN 1 Pounder Mk 6, Heavy
This cartridge was originally designed for a manually-loaded Hotchkiss gun which entered USN service in about 1890 and was also used in various other guns and sub-calibre training systems. It was adopted for two automatic weapons in the first few years of the 20[SUP]th[/SUP] century: an enlarged Maxim "Pom-pom" known as the One Pounder Maxim-Nordenfelt, Heavy, Mk 1 (later designated 1 pdr Mk 6), which during World War 1 was ordered in large numbers for the USN; and another US automatic cannon developed by Samuel N McClean (of Lewis Gun fame). Although the gas-operated McClean gun failed to be adopted by the USA, a sale to Russia during World War 1 subsequently led to the guns being widely distributed.
The brass cartridge case was rimmed and slightly bottlenecked. Various projectiles were used, but all seem to have been of the base-fuzed steel pointed type. The overall length of the round was 210 mm and the weight was around 600 g. The standard projectile weight was 476 g and the MV 640 m/s from an L/42.5 barrel.