The 37×145mmR was a series of rimmed-case, fixed-ammunition cannon shells for use in the 37mm Browning M4 autocannon.
The rapid strides in aircraft protection made it necessary to develop an aircraft weapon that would fire projectiles with greater explosive and armor-piercing qualities than smaller caliber weapons. As a result, the 37 mm (1.46 in) T9 automatic gun was developed. It was standardized for aircraft use as the M4 cannon in 1942.
The 37 mm (1.46 in) gun, M4, used the same high-explosive (M54) and practice (M55A1) projectiles as the 37 mm (1.46 in) antiaircraft gun, M1A2, but different cartridge cases were necessary due to the larger chamber of the M4 gun. The M4 was later replaced by the more powerful 37mm M9 autocannon.
High-explosive Tracer shell, 37 mm, M54 standardedit
This shell used the M56 point detonating fuze. The complete round weighs 1.99 lb (900 g); as fired, the projectile weighs 1.34 lb (610 g). The 0.16 lb (73 g) charge of M2 powder is a Hercules NG formula of single perforated grains with 0.03 in (0.76 mm) web and gives the projectile the prescribed muzzle velocity of 2,000 ft/s (610 m/s).
The M54 used a shell-destroying tracer in addition to the point-detonating fuze. The tracer had a burning time of three seconds at the end of which it set off an igniting relay charge of 1.68 gr (0.109 g) of Grade A-5 Army Black Powder which ignited a relay pellet that detonated the charge, destroying the shell before ground impact.
The bursting charge of tetryl weighed 0.10 lb (45 g), and the alternate Composition "A" charge weighs 0.105 lb (48 g). The tetryl loading consisted of a 200 gr (13 g) tetryl pellet pressed into the shell cavity under 9,000-10,000 psi (60-70 MPa) pressure and the remainder of the charge of two equal increments pressed under approximately 9,000 psi (62 MPa) pressure. The Composition "A" bursting charge is loaded in the same manner as the tetryl charge, except that the relay pellet with the Composition "A" weighs 36 gr (2.3 g) as against 23 gr (1.5 g) for the pellet used with the tetryl load.
Practice shell, 37 mm, M55A1 standardedit
This shell was the high-explosive shell modified slightly for practice purposes. It contained a red tracer and a dummy fuze (M50, M50B1, M50B2 or M50B3). The M50 dummy fuze was made from a plastic composition and the M50B1, M50B2 and M50B3 fuzes were made from low carbon steel machined to give the same contour and weight as the point-detonating fuze, M56, used with the M54 projectile.
As used in the M4, the complete round weighed 1.99 lb (900 g), and as fired the shell weighed 1.34 lb (610 g). The 0.16 lb (73 g) charge of M2 powder was Hercules NG formula of single perforated grains with a 0.03 in (0.76 mm) web and gave the prescribed muzzle velocity of 2,000 ft/s (610 m/s).
Armor-piercing shot, 37 mm, M80 standardedit
The overall length of the 37mm M-74 AP-T (Armor-Piercing shot with Tracer) and M-51 APCBC-T (Armor-Piercing Composite Ballistic-Capped shot with Tracer) armor-piercing projectiles used in the M3A1, M5A1, and M6 tank and antitank guns (37×223mmR), was too great to permit their use in the M4 gun. The 37 mm M80 AP-T shot was developed and standardized.
The M80 Armor-Piercing Tracer shot was a monoblock projectile with a tracer element of three seconds burning time. It did not need a fuze or bursting charge. The weight of the complete round was 2.31 lb (1.05 kg), the weight of the AP shot was 1.66 lb (750 g). The propelling charge was 0.15 lb (68 g) of M2 powder of a Hercules NG formula with a single-perforated grain and 0.03 in (0.76 mm) web.
Referencesedit
P-63 KingCobra - Browning M4 37mm Auto Cannon Gun
United States of America37 mm/56 (1.46") M4
April 11, 2024
145mmr, this, article, multiple, issues, please, help, improve, discuss, these, issues, talk, page, learn, when, remove, these, template, messages, this, article, includes, list, references, related, reading, external, links, sources, remain, unclear, because,. This article has multiple issues Please help improve it or discuss these issues on the talk page Learn how and when to remove these template messages This article includes a list of references related reading or external links but its sources remain unclear because it lacks inline citations Please help improve this article by introducing more precise citations August 2014 Learn how and when to remove this template message The topic of this article may not meet Wikipedia s general notability guideline Please help to demonstrate the notability of the topic by citing reliable secondary sources that are independent of the topic and provide significant coverage of it beyond a mere trivial mention If notability cannot be shown the article is likely to be merged redirected or deleted Find sources 37 145mmR news newspapers books scholar JSTOR February 2023 Learn how and when to remove this template message Learn how and when to remove this template message The 37 145mmR was a series of rimmed case fixed ammunition cannon shells for use in the 37mm Browning M4 autocannon The rapid strides in aircraft protection made it necessary to develop an aircraft weapon that would fire projectiles with greater explosive and armor piercing qualities than smaller caliber weapons As a result the 37 mm 1 46 in T9 automatic gun was developed It was standardized for aircraft use as the M4 cannon in 1942 The 37 mm 1 46 in gun M4 used the same high explosive M54 and practice M55A1 projectiles as the 37 mm 1 46 in antiaircraft gun M1A2 but different cartridge cases were necessary due to the larger chamber of the M4 gun The M4 was later replaced by the more powerful 37mm M9 autocannon Contents 1 Ammunition 1 1 High explosive Tracer shell 37 mm M54 standard 1 2 Practice shell 37 mm M55A1 standard 1 3 Armor piercing shot 37 mm M80 standard 2 ReferencesAmmunition editAmmunition was issued in the form of fixed rounds consisting of H E T shell M54 with Point Detonating fuze M56 Practice shell M55A1 with dummy fuze M50 A P shot M80 High explosive Tracer shell 37 mm M54 standard edit nbsp This shell used the M56 point detonating fuze The complete round weighs 1 99 lb 900 g as fired the projectile weighs 1 34 lb 610 g The 0 16 lb 73 g charge of M2 powder is a Hercules NG formula of single perforated grains with 0 03 in 0 76 mm web and gives the projectile the prescribed muzzle velocity of 2 000 ft s 610 m s The M54 used a shell destroying tracer in addition to the point detonating fuze The tracer had a burning time of three seconds at the end of which it set off an igniting relay charge of 1 68 gr 0 109 g of Grade A 5 Army Black Powder which ignited a relay pellet that detonated the charge destroying the shell before ground impact The bursting charge of tetryl weighed 0 10 lb 45 g and the alternate Composition A charge weighs 0 105 lb 48 g The tetryl loading consisted of a 200 gr 13 g tetryl pellet pressed into the shell cavity under 9 000 10 000 psi 60 70 MPa pressure and the remainder of the charge of two equal increments pressed under approximately 9 000 psi 62 MPa pressure The Composition A bursting charge is loaded in the same manner as the tetryl charge except that the relay pellet with the Composition A weighs 36 gr 2 3 g as against 23 gr 1 5 g for the pellet used with the tetryl load Practice shell 37 mm M55A1 standard edit This shell was the high explosive shell modified slightly for practice purposes It contained a red tracer and a dummy fuze M50 M50B1 M50B2 or M50B3 The M50 dummy fuze was made from a plastic composition and the M50B1 M50B2 and M50B3 fuzes were made from low carbon steel machined to give the same contour and weight as the point detonating fuze M56 used with the M54 projectile As used in the M4 the complete round weighed 1 99 lb 900 g and as fired the shell weighed 1 34 lb 610 g The 0 16 lb 73 g charge of M2 powder was Hercules NG formula of single perforated grains with a 0 03 in 0 76 mm web and gave the prescribed muzzle velocity of 2 000 ft s 610 m s Armor piercing shot 37 mm M80 standard edit The overall length of the 37mm M 74 AP T Armor Piercing shot with Tracer and M 51 APCBC T Armor Piercing Composite Ballistic Capped shot with Tracer armor piercing projectiles used in the M3A1 M5A1 and M6 tank and antitank guns 37 223mmR was too great to permit their use in the M4 gun The 37 mm M80 AP T shot was developed and standardized The M80 Armor Piercing Tracer shot was a monoblock projectile with a tracer element of three seconds burning time It did not need a fuze or bursting charge The weight of the complete round was 2 31 lb 1 05 kg the weight of the AP shot was 1 66 lb 750 g The propelling charge was 0 15 lb 68 g of M2 powder of a Hercules NG formula with a single perforated grain and 0 03 in 0 76 mm web References editP 63 KingCobra Browning M4 37mm Auto Cannon Gun United States of America 37 mm 56 1 46 M4 Retrieved from https en wikipedia org w index php title 37 145mmR amp oldid 1211281060, wikipedia, 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