U.S. M1911 & M1911A1 Arsenals & Markings
This page is a collector reference for U.S. M1911 and M1911A1 arsenal, depot, rebuild, inspection, proof, and ordnance markings. It explains what the markings generally mean and how they should be interpreted on military service pistols.
Important: This is not a serial-number page and it is not an individual pistol record. Serial numbers are intentionally not used as examples here. This page focuses on marks, arsenals, depots, and interpretation rules.
Marks Are Evidence
Arsenal and depot stamps can document later military inspection, rebuild, repair, storage, or service processing.
Not Manufacturer Marks
A rebuild mark usually identifies a later arsenal or depot, not the original pistol manufacturer.
Context Matters
Always read markings together with serial range, slide markings, barrel markings, finish, grips, and small parts.
Arsenal / Depot Marking Table
| Mark | Meaning | Collector Notes |
|---|
| AA | Augusta Arsenal | Arsenal rebuild, inspection, or service-processing mark. |
| AAA | Anniston Army Depot / Anniston arsenal-style marking reference | Recorded by collectors as an Anniston-related marking format. Interpret with full pistol context. |
| ANAD | Anniston Army Depot | Postwar depot rebuild or inspection marking. Often appears with date-style codes. |
| ANAD 7 76 | Anniston Army Depot, July 1976 | Month/year style Anniston marking. Indicates later depot processing, not WWII manufacture. |
| ANAD E 75 | Anniston Army Depot, 1975-era marking | Letter/year style Anniston marking. Record exactly as stamped. |
| BA | Benicia Arsenal | Arsenal inspection or service-processing mark. |
| FK | Frank Krack | Associated with Rock Island Arsenal marking practice during the 1941-1946 period, when Frank Krack was assistant foreman. |
| FKFK | Repeated / adjacent FK marking | Record exactly as observed. Treat as Rock Island Arsenal-related collector evidence when found with RIA and Rock Island flaming bomb stamps. |
| LEAD | Letterkenny Army Depot | Postwar depot inspection, storage, maintenance, or rebuild reference. |
| MR | Mount Rainier Ordnance Depot | Depot rebuild or inspection marking. |
| OG | Ogden Arsenal | Arsenal inspection or rebuild marking seen on U.S. military arms. |
| RA | Raritan Arsenal | Arsenal processing, storage, inspection, or rebuild marking. |
| RIA | Rock Island Arsenal | Arsenal rebuild, inspection, or service-processing mark. May appear with Rock Island flaming bomb stamps and FK markings. |
| RIA flaming bomb | Rock Island Arsenal ordnance-style stamp | Do not read this as the number 88. In this marking context, it is a Rock Island Arsenal flaming bomb stamp used during the 1941-1946 period. Multiple stamps may indicate multiple passes through RIA. |
| RR | Red River Arsenal / Red River Army Depot context | Arsenal or depot mark in rebuild context. Do not confuse with Remington Rand as a manufacturer name. |
| SA | Springfield Armory | Arsenal rebuild, overhaul, or inspection mark. Do not treat SA as the original maker unless the serial range and production context support Springfield manufacture. |
| SAA | San Antonio Arsenal | Arsenal rebuild or inspection marking. |
Rock Island Arsenal Marking Notes
RIA
User-owned reference photo showing an RIA mark.
RIA identifies Rock Island Arsenal. On M1911 and M1911A1 pistols, the mark is generally interpreted as evidence of arsenal rebuild, inspection, overhaul, or service processing.
Rock Island Flaming Bomb
Rock Island Arsenal flaming bomb stamps should not be read as the number 88. In this context, they are ordnance-style Rock Island stamps associated with the 1941-1946 marking period. More than one flaming bomb stamp should be recorded exactly as observed and may indicate more than one pass through Rock Island Arsenal.
FK / Frank Krack
FK is attributed to Frank Krack, assistant foreman at Rock Island Arsenal between 1941 and 1946. When FK or repeated FK markings appear with RIA and Rock Island flaming bomb stamps, record the combination as part of the pistol's Rock Island Arsenal service history.
Anniston Army Depot Marking Notes
ANAD
ANAD identifies Anniston Army Depot. These markings are generally associated with postwar depot rebuild, inspection, or maintenance work. Pistols marked ANAD may show mixed slides, replacement parts, arsenal finishes, and later service history.
Date Codes
Anniston markings may include date-style codes. ANAD 7 76 is interpreted as July 1976. ANAD E 75 should be recorded as a 1975-era Anniston marking unless additional documentation clarifies the exact date-code system.
Springfield Armory Marking Notes
SA
SA can indicate Springfield Armory rebuild, overhaul, or inspection work. This is an arsenal marking and should not automatically be treated as the original manufacturer. Always compare the serial range, slide marking, frame marking, and production context before assigning original manufacture.
Other Arsenal and Depot Notes
Augusta Arsenal — AA
AA is generally interpreted as Augusta Arsenal rebuild, inspection, or service processing.
Ogden Arsenal — OG
OG markings are collector references for later inspection, storage, or rebuild channels.
Benicia Arsenal — BA
BA marks are less common than AA, SA, or RIA, but remain relevant for service-history documentation.
Raritan Arsenal — RA
RA markings indicate Raritan Arsenal processing, inspection, storage, or rebuild history.
Red River Arsenal / Depot — RR
RR can mean Red River Arsenal in rebuild-marking context. This is different from Remington Rand manufacturer identification.
San Antonio Arsenal — SAA
SAA markings indicate San Antonio Arsenal rebuild, inspection, or service processing.
Modern Depot and Arsenal Mission Context
The current missions of U.S. Army depots and arsenals help explain why these facilities are important in the broader military maintenance system. Modern missions do not automatically prove a specific M1911 or M1911A1 passed through that facility; pistol markings still have to be interpreted from the actual stamp, location, date code, and historical context.
| Facility | Location | Modern Mission Context |
|---|
| Anniston Army Depot | Anniston, Alabama | Specializes in recapitalization and heavy repair of combat vehicles, including Abrams tank work, artillery, and related ground-combat systems. |
| Corpus Christi Army Depot | Corpus Christi, Texas | Department of Defense rotary-wing aircraft repair and component-overhaul facility. |
| Letterkenny Army Depot | Chambersburg, Pennsylvania | Focuses on tactical missiles, air defense systems, and ground support equipment. |
| Red River Army Depot | Texarkana, Texas | Primary hub for refurbishment of tactical wheeled vehicles, Bradley Fighting Vehicles, and multiple launch rocket systems. |
| Tobyhanna Army Depot | Tobyhanna, Pennsylvania | Full-service electronics maintenance facility for communications, radar, and missile-guidance systems. |
| Rock Island Arsenal Joint Manufacturing and Technology Center | Rock Island, Illinois | Manufactures and refurbishes deployable metal parts, mobile maintenance shops, and large weapons components. |
| Watervliet Arsenal | Watervliet, New York | Manufactures and refurbishes cannon tubes, mortars, and large-caliber artillery systems. |
Proof, Ordnance, and Inspection Marks
| Mark Type | Meaning | How to Record It |
|---|
| Flaming Bomb | Ordnance-style inspection or arsenal marking, depending on location and style. | Record exact location, count, and whether the style matches a known arsenal marking pattern. |
| RIA Flaming Bomb | Rock Island Arsenal flaming bomb stamp in the 1941-1946 RIA/FK marking context. | Do not record as 88. Record as one or more RIA flaming bomb stamps. |
| Inspector Initials | Government inspection or arsenal personnel markings. | Record exactly as stamped. Do not expand initials unless the attribution is supported by collector references or known context. |
| Rebuild / Depot Stamp | Later arsenal or depot processing mark. | Record mark, placement, depth, date code, and whether finish appears applied before or after the stamp. |
Grip Marking Sidebar
Mixed Grips on Service Pistols
Arsenal-rebuilt pistols may show mixed grips. Colt-style plastic grips often have large reinforcing rings around the screw holes. Keyes grips have their own reinforcement and mold-number characteristics. Mixed left and right grips should be recorded as observed and may be consistent with rebuild or service history.
Interpretation Rules
| Rule | Explanation |
|---|
| Marks are not always maker marks | Arsenal and depot marks usually show where a pistol was inspected, rebuilt, or processed after original manufacture. |
| Context controls meaning | The same letters may mean different things depending on location, date, and pistol context. RR is Red River Arsenal in rebuild context, but Remington Rand in manufacturer context. |
| Modern mission is background | A facility's modern mission helps explain its role in the Army maintenance system, but pistol interpretation still depends on the actual mark and historical period. |
| Record what is visible | Record exact letters, numbers, count, placement, and uncertainty. Avoid forcing unclear marks into known categories. |
| Separate evidence from conclusion | A mark may support a rebuild history, but final interpretation should consider finish, parts, barrel, slide, frame, and documentation together. |
Research Disclaimer: Marking identification is based on observed collector references and known U.S. military rebuild practices. Some marks vary by depth, location, strike quality, and finish wear. Always evaluate markings with the full pistol context, including serial range, manufacturer, slide markings, barrel markings, finish, grips, and small parts.