Barrel Markings

Colt M1911 (1911 – 1919)

COLT M1911
Upright sans serif H, from circa S/N 6,500 to around 20,000

COLT M1911
H moved to the top of the chamber, first appearance of mark on underside, circa S/N 20,000 through 25,000

COLT M1911
P proof mark first appeared at S/N 24,251. It remained in this location until around S/N 25,000

COLT M1911
“Horizontal H P” marking from circa S/N 25,000 to about S/N 120,000. (First appearance of marking on lower barrel lug)

COLT M1911
“Vertical H P” from circa S/N 110,000 to about S/N 425,000

COLT M1911
“Common Leg HP” from circa S/N 400,000 to the end of M1911 Production at S/N 629,500

Colt M1911 A1 (1924 – 1945)

COLT “Improved” M1911 (1924 Transitional)
From S/N 700,001 through S/N 710,000 (First appearance of the M1911-A1 barrel configuration

COLT M1911 A1
“COLT 45 AUTO / P” 1937 production, S/N 710,001 through 712,349 (no “Small G”)

COLT M1911 A1
“COLT 45 AUTO / P / Small G” from circa S/N 712,350 to around S/N 832,000 (1938 to late 1942)

COLT M1911 A1
“Commercial/Military” from circa S/N 856,000 to around S/N 897,000 (Commercial barrels transferred to military contract)

COLT M1911 A1
“Large G” marking began circa S/N 786,000 to around S/N 953,000 (later examples often have a second mark, i.e. G/F)

COLT M1911 A1
Colt “F” from circa S/N 935,000 to around S/N 1,118,000, followed by Colt “7” intermixed through end of production

COLT M1911 A1
Colt “Boxed C” from circa S/N 1,710,000 through end of production

Springfield Armory M1911 (1915 – 1923)

SPRINGFIELD ARMORY M1911
From circa S/N 72,571 to around S/N 77,000

SPRINGFIELD ARMORY M1911
From circa S/N 77,000 to around S/N 83,855

SPRINGFIELD ARMORY M1911
From circa S/N 102,597 to S/N 107,596

SPRINGFIELD ARMORY M1911
From circa S/N 113,497 to end of production

SPRINGFIELD ARMORY M1911
Post WW1 replacement barrel

SPRINGFIELD ARMORY
M1911 A1 (1924 – 1943)

Springfield Armory M1911 A1
Pre WWII replacement barrel

Springfield Armory M1911 A1
Field and Armory replacement barrels. Limited usage in early Ithaca and Remington Rand production (143,098 barrels manufactured from July 1, 1941 through June 30, 1943)

Springfield Armory M1911 A1
Field and Armory replacement barrels. Near the end of production in June 1943 when Heat Lot Codes were discontinued. “Crossed Cannons” Ordinance Dept. inspection was stamped on right lower lug

REMINGTON ARMS-UNION METALLIC CARTRIDGE
M1911 (1918 – 1919)

Remington Arms-Union Metallic Cartridge Co. M1911
From circa S/N 1 to around 1,000

Remington Arms-Union Metallic Cartridge Co. M1911
From circa S/N 1,000 through end of production

M1911 A1 Contract Manufacturers (1941 – 1945)

Singer Mfg. Co.
Singer M1911 A1’s (500 pistols)

High Standard Mfg. Co.
Ithaca, Remington Rand, and Union Switch & Signal M1911 A1’s

Flannery Bolt Co.
Field and Armory replacement barrels. Small quantities used by Ithaca & Remington Rand in 1944 and 1945 production.