Colt 1911 Slide Serial Number Location
Frame and Slide MarkingsFrame and Slide MarkingsAlwaysExamine The Markings With A Magnifier:The markings that were applied to a metal surfaces of various military1911/1911A1 pistols were applied both before and after the finalpolishing/finishing was done. Somespecific markings, such as the final acceptance mark and the OrdnanceAcceptance mark were always done after finishing. Other marks such as the standard slide manufacturers identificationslide legend were always done before final finishing. Still other marks such as the serial number were (depending on thetime period and the manufacturer) applied before, after and both beforeand after. An example of bothbefore and after is the serial number of the post mid 1943 Remington Randsor Ithacas.The “NO.”prefix was roll marked at the same time the right hand receiver legend(United States Pro) was marked. Thenafter finishing and inspection, the serial number was stamped.
1911A1pistols before mid 1943 had the serials stamped on before finishing. Early 1911 Colts up to about serial 7500 had their serials stampedafter the finish was applied. Thiswas about the same time that the serial number location was moved to belowthe trigger. Examiningthe markings will help determine if the pistol has been refinished, and itwill certainly help to determine if the markings are original orcounterfeit. However athorough knowledge of what the markings are supposed to look like on anyspecific pistol is generally necessary. Markings that were applied before finishing will usually haveall traces removed of the ridges created when the stamping die displacesmetal. Often the ridges are hard to see.
Another clue, especially on blued pistols, is around the stampswhere metal is displaced, the finish will often flake off in microscopicchips that will leave a white shadow appearance around the letters. If the pistol is blued after these stamps, the micro flaking ishighly unlikely. Only bystudying lots of pistols will one know what he is looking at, and that isgetting to be more and more difficult. Was the stamp before or after finish.These will be indicated in the descriptions below. These marks will have awhite or burnished appearance.
Also remember that when metal is stamped itis pushed a side and will create a ridge. A powerful magnifying glass isessential to see the ridges and the detail around them. Ifthe ridge is absent and it should be there, The pistol most likely hasbeen refinished. Refinished guns are worth much less then guns with theoriginal finish. Markingsthat are applied after finish are Arsenal Inspectors marks, sometimes firingproofs, and the Ordinance Escutcheon (Cross Cannons). 'Rampant Colt' details by serial numberCircled, rear located Rampant Colt:1 to 20000 approx.Non-circled, rear located RampantColt.20,000 to 285,000 approx.Non-circled, middle located RampantColt. 285,000 to end of production approx.Serial number placement (M1911 and M1911A1)About Serial Number 1 to 4500(Stylized numbers to about 4500)4500 to 7500(Prefix to underline 0, font changed to BLOCK)7501 to end of production(Moved to behind slide stop hole)Colt SN 710001 to about 1139xxx)Colts between serial number 710001 andabout 1139XXX have the serial number also underneath the firing pinstop plate.'
Colt 1911 Serial Numbers
United States Property' mark locationFrom Serial Number 1to about 510000From Serial Number about 500000to end of productionIthaca slide markingsThe 'Model of 1911 A1U.S. ARMY' marking on the right side of the slide is normally foundin the range from 906000 to 916404.Remington Rand serialnumber variationsRR halted production in 1943, When theyresumed production the line from under the ' O' in 'N O'in front of the serial number was removed (see IMAGE above).
This transition started at approximately 955000. ( Toppre 955000, Bottom post 955000)Remington Rand slide markings variationsType 1 Slide: Observed from 916405 toapproximately 955000Type 2 Slide: Observed fromapproximately 927000 to about 1015000Type 3 Slide: Observed from approximately 980000 to end ofproduction. RR legend is shorter then the slide stop.US & S 'P' proof markingsTheproof was absent to about 1,060,000 (ref Charles Clawson). From about 1060100 to1082000, the P proof was applied at the left edge of the slide andon the frame.
From about 1082000 to the end of production the P wasplaced centered in front of the rear sight and on the frame.See example below SN range105xxxx. On the EXP US&S pistols the ones that I have observed havea P on the the slide but not receiver. There is no Inspectorscartouche on the ESP marked pistols.US&S absent proof marksNotice P on this US&S slide is offcenter and located in lower left of this image, this is notuncommon.(Click on image for larger version).Listing of known slide andframe/receiver markings (not complete): Augusta Arsenal. Found on the receivers of guns rebuiltor inspected atthe arsenal.:Rock Island Arsenal. Found on the receivers of guns rebuilt orinspected at the arsenal.: Springfield Arsenal Rebuild StampANAD/AN: Anniston Army Depot (Anniston,Alabama) observed with a date stamp following it (MM YY) in 1975: Can be found on top of slides on WWII A1s as well as on theBarrel and Frame below the clip (magazine) release.: This stamp is found on the frame and slidesof 1911s manufactured for and owned by the US armed forces. In most casesa gun with the property stamp will not have a 'c' in the serialnumber.: locatedafter finish by thedisconnector ontop of the frame indicates field service.: Located on top of frame bydisconnector indicates gun was made tofill a Government contract. Stamped before the finish is applied.or H:Provisional acceptance mark.
Located on top of frame bydisconnector indicates gun inspectedby Ordinance Inspector. Stamped before finish applied. Hosmerused this stamp on Colts 1911s and M1917 revolvers from 1911 to1919. Also found on barrels and slides.Inspectors cartouche and Arsenal rebuildstamp examples1942 Colt WB Example1912 Colt WGP ExampleAugusta ArsenalRebuild StampInspection initials found on 1911/1911A1s;located under the slide stop on the left side of the gunWalter G.
Penfield, Major Colt S/N 1-101,500Gilbert H. Found on Colt M1911s SN 101,500 to230,000, M1907, M1917, M1903, and M1 rifles at different periods.J.M.Gilbert found on Colt 1911s from 1917 to 1918 SN 230,001 to 302,000.This replaced the personalized monograms aboutS/N 300,000 to end of WWI production (1919)Frank J.Atwood. Found on Remington Rand and Ithaca 1911A1s (entireproduction).: Edmund E. Chapman Remington UMC S/N 1-21676: Walter T Gorton Colt S/N 700,000-710,000Charles S Reed Colt S/N 717,282-723,000RS: Robert Sears Colt S/N 723,000 to 750,500Waldemar BrobergColt S/N 750,500 to 861,000: Guy H. Drewry Colt S/N 845,000 to 2,360,600: John S. Begley, very late 1945 Colt 1911 A1 toend of WWII production(1945-Very rare)Arsenal Inspectors from Rock Island:EB: Elmer Bjerke was promoted on January 6th, 1947 to Formanof small arms inspection.
Colt 1911 Slide Serial Number Location 302
He was responsible for the finalinspection of new and overhauled small arms. He served in thatcapacity until 1958. All small arms inspected under his supervisionbear the markings 'RIA' for Rock Island Arsenal and 'EB' for ElmerBjerke.: Frank Krack was Assistant Foreman of the InspectionDivision at RIA from September 17, 1941 until he retired on July19th, 1946. During that period all small arms inspected underhis supervision would be stamped with his initials 'FK' as well asthose of the Rock Island Arsenal 'RIA'.Parkerized/blued bullet feed ramp finishBullet feed ramps where blued in receivers toserial number 710,000, then at SN 710,001 they where machined after thereceiver was blued or parkerized, leaving this area of the gun in thewhite and unfinished. This area should show machine marks and not bepolished. In mid-1944 Colts bullet feed ramps where parkerized, this beganat approximately SN 1700000.Rev 1.1c.