Appendix K
World War II Development of the Marine Infantry Regiment¹

Part 1--Infantry Regiment T/Os

See also Staff Officer's Field Manual for Amphibious Operations --HyperWar

Unit	D Series	E Series	F Series	G Series	Notes
Infantry Regiment	3,168	3,242	3,218	3,412
H&S Company	(173)	(186)	*(261)	(249)	*Company supply section became a service platoon
Weapons Company	(196)	(197)	(203)	(175)
Ccompany Hq	(48)	(69)	(71)	(51)
75mm SP Gun Platoon	(34)	(26)	*(36)	**	*Increase of two 75mm guns (total of four) in each platoon. **75mm gun platoon replaced by a 105mm howitzer (self-propelled) platoon.
3 AA and AT Platoons	(38)
3 37mm Gun Platoons		(34)	(32)	*(40)	*Reduced to two platoons without reduction in number of guns.
105mm SP Howitzer Platoon				(44)
3 Infantry Battalions	(933)	(953)	(918)	(996)
Headquarterrs Company	(111)	(137)	(213)	(270)
Battalion Hq	(75)	(123)	(138)	(131)
Company Hq	(36)	(14)	(17)	(26)
81mm Mortar Platoon			(58)	(58)
Assault Platoon				(55)
Platoon Hq				(10)
3 Asslt Secs				(15)
SecHq				(1)
2 Asslt Sqds				(7)
Weapons Company	(273)	(228)
Company Hq	(29)	(41)
20mm AA & AT Plt	(24)
81mm Mortar Plt	(76)	*(58)	**		*Platoon strength reduced without reduction of mortars. **Mortar platoon placed in battalion headquarters company.
3 Machine Gun Plts	(48)	(43)	*		Machine gun platoon placed in rifle company.

Unit	D Series	E Series	F Series	G Series	Notes
3 Rifle Companies	(183)	(196)	(235)	(242)
Company Headquarters	(29)	(28)	(53)	(51)
Hq Sec			(33)	(31)
60mm Mort Sec			(20)	(20)
Weapons Platoon	(28)	(39)
Plt Sec	(4)	(4)
60mm Mort Sec	(11)	*(16)			*An addititonal mortar and machine gun added to platoon; which now consisted of 3 mortars and 3 machine guns.
Lt MG Sec	(13)	*(19)	( )	( )
Machine Gun Plt			*(44)	**(56)	*F-Series platoon had 12 machine guns; 6 air-cooled, and 6 water-cooled. **G-Series T/O platoon given an additional two guns.
3 Rifle Platoons	(42)	(43)	(46)	(45)
Platoon Hq	(7)	(7)	(7)	(6)
BAR Squad	(8)
3 Rifle Sqds	(9)	*(12)	(13)	(13)	*BAR Sqd dropped; platoon now consists of three rifle squads.

Part 2--Infantry Regiment Equipment

See also Staff Officer's Field Manual for Amphibious Operations --HyperWar

Item	D Series	E Series	F Series	G Series	Notes
WEAPONS
Carbine, .30 caliber, M1	943	1,405	1,794	1,383
Flamethrower, portable, M2-2			81	36
Gun:
20mm, AA & AT	18
37mm, AT		12	12	8
75mm, SP	2	2	4
Gun, Machine:
.30 caliber, M1917A1	72	36	54	54
.30 caliber, M1919A4	36	69	65	66
.50 caliber, heavy-barrel, flexible	8	16	12	10
Gun, submachine, .45 caliber, with folding stock	507
Howitzer, M7, self-propelled				4
Launcher:
AT	47
Grenade, AT, M1	97

Item	D Series	E Series	F Series	G Series	Notes
Rocket, AT, M1		53	43
Rocket, 2.36-inch, M9A1 or A18				35
Mortar:
60mm	18	27	39	39
81mm	12	12	12	12
Pistol, automatic, .45 caliber	17	*	*	408	*Carbines replaced Pistols in the infantry and artillery regiments in E- and F-Series T/Os.
Rifle:
.30 caliber, M1	1,385	1,673	1,179	1,393
.30 caliber, M1903	97
.30 caliber, automatic, Browning, M1918M2	162	162	243	243
Shotgun, 12-gauge		100	100	100
TRANSPORTATION
Ambulance, 1/4-ton, 4x4		5	5	5
Station wagon, 4x4	2	2
Truck:
1/4-ton, 4x4	55	48	36	34
1/4-ton, radio-equipped		11	8	12
1-ton, 4x4, cargo	8	8	23	20
1-ton, 4x4, light repair	1	1	2

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Footnotes

1. The material in this appendix is derived from the D-, E-, F-, and G-Series Tables of Organization for each of the above units (Tables of Organization Subject File, HRS, HistBr, HQMC).