. . "The Rock Island Arsenal publication titled NOTES ON THE BROWNING MACHINE GUN CAL. .30 M1919A4 dated March 18, 1937 set forth everything that you needed to know about the weapon conversion program right down to Section VIII Paragraph 2 which instructs which type of lubricant (class A or Navy contract oil 2110) and cautions that the Bolt, barrel guide, extension and other moving parts should be c" . . .