I.  | 
	Introduction | 
	1 | 
	II.  | 
	Small  Arms | 
	5 | 
 
	|   | 
	a.  | 
	Definition and Procurement Summary | 
	5 | 
 
	|   | 
	b.  | 
	Procedure for Small Arms Procurement | 
	6 | 
 
	|   | 
	c.  | 
	Problems | 
	10 | 
 
 
	|   | 
	  | 
	1.  | 
	Spare  Parts  | 
	11 | 
 
	|   | 
	  | 
	2.  | 
	Supply and Repair | 
	12 | 
 
	|   | 
	  | 
	3.  | 
	Caliber .38 Special Ammunition Assembled with Unjacketed Bullets | 
	15 | 
 
 
	|   | 
	  | 
	4.  | 
	Belted Ammunition  | 
	19 | 
 
	|   | 
	  | 
	5.  | 
	Packaging | 
	19 | 
 
 
	III.  | 
	Caliber .50 AA Machine Gun | 
	21 | 
 
	|   | 
	a.  | 
	Development | 
	21 | 
 
 
	|   | 
	b.  | 
	Procurement | 
	25 | 
 
 
	IV.  | 
	1.1" AA Machine Gun | 
	29 | 
 
	|   | 
	a.  | 
	Early History | 
	29 | 
 
	|   | 
	b.  | 
	Production | 
	34 | 
 
 
	|   | 
	  | 
	1.  | 
	Guns and Mounts | 
	34 | 
 
	|   | 
	  | 
	1.  | 
	Power Drives  | 
	38 | 
 
	|   | 
	c.  | 
	Distribution and Dispositions | 
	42 | 
 
	V.  | 
	20mm Antiaircraft Gun  | 
	45 | 
 
	|   | 
	a.  | 
	Introduction | 
	45 | 
 
 
	|   | 
	b.  | 
	Background and Adoption of 20mm | 
	47 | 
 
	|   | 
	  | 
	1.  | 
	Early British Activities | 
	47 | 
 
	|   | 
	  | 
	2.  | 
	Reason for Selection of Oerlikon Over the Hispano-Suiza | 
	53 | 
 
 
	|   | 
	c.  | 
	Production Program  | 
	57 | 
 
	|   | 
	  | 
	1.  | 
	Preliminary Contract Negotiations | 
	57 | 
 
	|   | 
	  | 
	2.  | 
	Increasing Requirements  | 
	64 | 
 
	|   | 
	  | 
	3.  | 
	Mounts | 
	68 | 
 
 
	|   | 
	  | 
	4.  | 
	Cutbacks and Terminations | 
	77 | 
 
	|   | 
	  | 
	5.  | 
	Costs | 
	81 | 
 
 
	|   | 
	  | 
	6.  | 
	Speeding Production | 
	84 | 
 
	|   | 
	d.  | 
	Distribution | 
	95 | 
 
 
	|   | 
	e.  | 
	Future of the 20mm Gun | 
	98 | 
	VI..  | 
	40mm Bofors Gun | 
	102 | 
 
	|   | 
	a.  | 
	Introduction | 
	102 | 
 
 
	|   | 
	b.  | 
	Adoption  of Gun by the U.S. Navy | 
	103 | 
 
	|   | 
	  | 
	1.  | 
	Critical Antiaircraft Situation | 
	103 | 
 
	|   | 
	  | 
	2.  | 
	Purchase of a 20mm Bofors Gun | 
	107 | 
 
	|   | 
	  | 
	3.  | 
	Testing Period | 
	112 | 
 
	|   | 
	  | 
	4.  | 
	Negotiations of Contract for Manufacturing Rights | 
	117 | 
 
 
	|   | 
	c.  | 
	Production Program  | 
	127 | 
 
	|   | 
	  | 
	1.  | 
	Early Design Problems | 
	127 | 
 
	|   | 
	  | 
	2.  | 
	Overall Performance Program | 
	130 | 
 
	|   | 
	  | 
	 | 
	  (a) Initial Procurement Plans, 1941 | 
	130 | 
 
 
	|   | 
	  | 
	 | 
	  (b) Development of the Procurement Pattern | 
	132 | 
 
 
	|   | 
	  | 
	3.  | 
	Associated Equipment | 
	139 | 
 
	|   | 
	  | 
	 | 
	(a) Power Drives | 
	139 | 
 
	|   | 
	  | 
	 | 
	(b) Fire Control | 
	147 | 
 
	|   | 
	  | 
	 | 
	(c) Ammunition | 
	149 | 
 
	|   | 
	  | 
	4.  | 
	Requirements | 
	153 | 
 
 
	|   | 
	  | 
	5.  | 
	Special Problems | 
	159 | 
 
	|   | 
	  | 
	 | 
	(a) Continuing Design Problems | 
	139 | 
 
	|   | 
	  | 
	 | 
	(b) Balancing Production | 
	161 | 
 
	|   | 
	  | 
	 | 
	(c) York Safe and Lock Company | 
	163 | 
 
	|   | 
	  | 
	 | 
	(d) Machine Tools, Materials, and Priorities | 
	166 | 
 
 
	|   | 
	c.  | 
	Use and Performance  | 
	171 | 
 
	|   | 
	  | 
	1.  | 
	General Characteristics  | 
	171 | 
 
	|   | 
	  | 
	2.  | 
	Distribution | 
	174 | 
 
 
	|   | 
	  | 
	3.  | 
	Antiaircraft Performance  | 
	178 | 
 
	|   | 
	  | 
	4.  | 
	Maintenance and Performing Problems | 
	180 | 
 
	|   | 
	  | 
	5.  | 
	Possibilities with Blind Firing Directors | 
	182 | 
	VII.  | 
	3" Guns  | 
	184 | 
 
	|   | 
	a.  | 
	Introduction | 
	184 | 
 
 
	|   | 
	b.  | 
	Dual Purpose Mounts | 
	188 | 
 
	|   | 
	  | 
	1.  | 
	Single Mount Mark 24 | 
	188 | 
 
	|   | 
	  | 
	2.  | 
	Single Mount Mark 22 | 
	189 | 
 
	|   | 
	c.  | 
	Twin Mount Mark 27 | 
	191 | 
 
	|   | 
	d.  | 
	Production Program  | 
	192 | 
 
	|   | 
	  | 
	1.  | 
	Schedule of Requirements | 
	192 | 
 
	|   | 
	  | 
	2.  | 
	Assemblies | 
	193 | 
 
 
	|   | 
	  | 
	3.  | 
	Mounts | 
	195 | 
 
 
	|   | 
	  | 
	4.  | 
	Power Drives  | 
	197 | 
 
	|   | 
	  | 
	5.  | 
	Associated 3"/50 Equipment | 
	198 | 
	VIII.  | 
	4"/50 Mount Mark 12 Mods | 
	200 | 
 
	|   | 
	a.  | 
	Introduction | 
	200 | 
 
 
	|   | 
	b.  | 
	History and Characteristics | 
	200 | 
 
	|   | 
	c.  | 
	Procurement | 
	201 | 
 
 
	|   | 
	d.  | 
	Procurement | 
	43 | 
 
	IX.  | 
	5" Guns | 
	203 | 
 
	|   | 
	a.  | 
	Introduction | 
	203 | 
 
 
	|   | 
	  | 
	1.  | 
	5"/38 Guns  | 
	203 | 
 
	|   | 
	  | 
	 | 
	(a) 5"/38 Base Ring Mounts | 
	204 | 
 
	|   | 
	  | 
	 | 
	(b) 5"/38 Pedestal Mounts Mark 24 and Mod 2 | 
	205 | 
 
 
	|   | 
	  | 
	 | 
	(c) 5"/38 Twin Mounts Mark 28 Mods, Mark 29 Mods, Mark 32 Mods, and Mark 38 Mods | 
	205 | 
 
	|   | 
	  | 
	2.  | 
	5"/25 Guns  | 
	206 | 
 
	|   | 
	  | 
	3.  | 
	5"/54 Guns  | 
	206 | 
 
	|   | 
	b.  | 
	History of 5"/38 | 
	207 | 
 
	|   | 
	  | 
	1.  | 
	Prewar Development of 5"/38; The Mark 37 Merchant Mount | 
	207 | 
 
 
	|   | 
	  | 
	 | 
	(a) Inauguration of Program to Arm Merchant Vessels | 
	207 | 
 
 
	|   | 
	  | 
	 | 
	(b) Selection of 5"/38, Extensively Modified, for Merchant Arming Program | 
	208 | 
 
 
	|   | 
	  | 
	2.  | 
	Status of 5"/38 Program at Beginning of War | 
	211 | 
 
 
	|   | 
	  | 
	 | 
	(a) 5"/38 Caliber Single Mounts (Base Ring Type) for DD's and Auxiliaries | 
	211 | 
 
 
	|   | 
	  | 
	 | 
	(b) 5"/38 Gun and Single Pedestal Mount Assembly | 
	213 | 
 
 
	|   | 
	  | 
	 | 
	(c) 5"/38 Twin Gun and Mount Assembly | 
	214 | 
 
 
	|   | 
	  | 
	3.  | 
	Production Program During the War | 
	216 | 
 
	|   | 
	  | 
	 | 
	(a) 5"/38 Merchant Mount Mark 37 | 
	220 | 
 
 
	|   | 
	  | 
	 | 
	(b) 5"/38 Pedestal Mounts | 
	222 | 
 
	|   | 
	  | 
	 | 
	(c) 5"/38 Caliber Single Mount Mark 30 (Base Ring Type) | 
	228 | 
 
	|   | 
	  | 
	 | 
	(d) 5"/38 Twin Gun Mount Assembly | 
	228 | 
 
 
	|   | 
	c.  | 
	History of 5"/25 | 
	232 | 
 
	|   | 
	  | 
	1.  | 
	Development | 
	232 | 
 
	|   | 
	  | 
	2.  | 
	Production Program  | 
	232 | 
 
	|   | 
	d.  | 
	History of 5"/54 Mount | 
	236 | 
 
	|   | 
	  | 
	1.  | 
	Development | 
	236 | 
 
 
	|   | 
	  | 
	2.  | 
	Production Program  | 
	241 | 
	X.  | 
	6"/47 Gun  | 
	241 | 
 
	|   | 
	a.  | 
	Introduction | 
	241 | 
 
 
	|   | 
	b.  | 
	History of 6"/47 Dual Purpose Twin Mount | 
	241 | 
 
 
	|   | 
	c.  | 
	Plans for Proposed 6"/47 Twin Turret | 
	249 | 
 
 
	|   | 
	d.  | 
	6"/47 Triple Turret Production Program | 
	250 | 
 
 
	XI.  | 
	8"/55 Gun   | 
	253 | 
 
	|   | 
	a.  | 
	Introduction | 
	253 | 
 
 
	|   | 
	b.  | 
	History of 8"/55 Caliber Turret for CA-139 Class Cruiser | 
	253 | 
 
 
	|   | 
	c.  | 
	Production Program for CA 68-75 and 122 Class Cruiser | 
	271 | 
 
 
	XII.  | 
	12"/50 Gun  | 
	273 | 
 
	|   | 
	a.  | 
	Introduction | 
	273 | 
 
 
	|   | 
	b.  | 
	History of 12"/50 Three-Gun Turret | 
	273 | 
 
	XIII.  | 
	16" Guns   | 
	282 | 
 
	|   | 
	a.  | 
	Introduction | 
	282 | 
 
 
	|   | 
	b.  | 
	Development in 16" Guns | 
	282 | 
 
	|   | 
	c.  | 
	Production Program  | 
	286 |