ColtModel 1911 Caliber .455 Weblev Convertedto .45ACP

Byj CaptainLior Nedivi, lsrael NationalPolice HQ, Divisionof Identificationand Forensic Science,Weapons Identification Laboratory.

Key Words: mismatchingof ammunition,Colt, ,455Webley Automatic, .45 ACP,fi rearmconversion. Abstract

Colt model1911, caliber.455 Webley Automatic, was convertedto caliber .45ACP dueto rarity of originalammunition. This is a caseof "mismatchingof ammunition" where th€ firearm was conv€rtedto fit the ammunition,not vice yersa as commonly performed. This firearm conversionled to the changeof familyand individualcharacteristics on thebullets and cartridge cases.

The phenomenaof "mismatchingof arnmunition" has been describedby Hatcher, Jury ard Weller,in their book Firearm Investigation,Identification and Evidence(pp 311-315),but more in the contextof physicallychanging the ammunitionto fit the firearm. The most common tlpe of "mismatchingof arxnunition",according to Hatcheret al. and casesreceived by our laboratory, is where the bullet caliber is the samebut the cartridgecase is wrong. The substitute cartridgecase is simplyloaded and fred. Othert)pes of mismatchingis doneby simpiyfiling or grindingoffrims ofrevolver amrnunitionso it will functionin an automaticpistol. Still another,a bit ofcopperwire or evena paperclip couldbe usedon rimlesscartridge cases to achievea rim for usein revolvers;a muchbetter method than having to elevatethe barreito aid in fuing pin pressure to the prirner.The list is long.This articlegives an exampleof'lnismatching of ammunition"by convertng a firea.m to fit ammunitionof a different caliber and to the best of our knowledgeit is the fust timethis kind ofconversionis reported.

Our firearmslaboratory received a Colt Model 1911,semi automaticpistol, chamberedfor caliber.455 WebleyAutol'natic amrnunition for examination;a caseof illegal possession.See photograph1. Thesepistols were made in smallquantities, mainly for the Britishmarket. They are so rarein Israel,it is abnostimpossible to obtainone from an Israeligun dealers.There is not even onepistol legally registered in thenaiional computerized data base.

u\Theowner ofthe pistolprobably encounteredthe problemof obtainingoriginal .455 Webley Automaticammunition for his gun,therefore he rradea smallconversion to makeit possibleto fire the verypopular .45 ACP ammunition.

Fromthe firearmexaminer's point ofview, anyconversion brings in someproblems and raises quesdons:

l. Beingaware that the conversioncould be usedto coverup a misuseofthe firearm. 2. Identi8,ingthe fact that there hasbeen "a change"and how it affectsthe fuearmsfunctioning. 3. Findinga way to restorethe firearmto its originalcondition, ifnecessary. 4. A changein the classand individual characteristics ofthe bulletsand caltri.loa ^qcac Previous to test fuing the pistol, an attempt to chamber.455 Webley Automatic arnmunition fiom the laboratory supply was made.It was unsuccessfuldue to an altered extractor hook. This "gunsmith" simply replaced the original extractor with a home made one which has a longer exlractionhook. An altemtjonnecessary to reachthe smallerdiameter rim of the .45 ACP. See photograph2 for the comparisonofextactor hooklengths.

This simple conversionwas possibledue to the $nall differencesin the dimensionsof the two caiibers,.455 Webley Automatic and .45 ACP. Seephotograph 3 andtable I for technicaldata of bothcalibers. The pistol was then test fired with.45 ACP anmunition.

Later,an original.45 ACP Colt Model l9l lAl extractorwas disassembled from our laboratory collectionand assembledon the subjectpistol. This enabledloading and test firing with .455 WebieyAutomatic ammunition. It wasassumed that the originalextractor hook ofthe Coll 1911 caliber.455 Webley has the samedimensions as the Colt l9l lAl caliber.45 ACP.

The test fued cartidges and bullets, liom both calibers, could now be comparcd to the collectionofspent bullets and cartridges ftom unsolvedcrime cases, The test bullets ofcaliber .455 WebleyAutomatic had six 'hormal" distinctive land impressionswith a left hand twist. The width of the iand impressionsof the test bullers of caliber .45 ACP were not clear, characteristicof an oversizedbore or undersizedbullet or a barrel with erodedland impressions.Only one land impressionhad what appearedto be distinctive driving and leading edges. However the land impressionwidth measured0.094 inch (2.4 mm) as comparedto the .455 Webleytest bullet and pistolbarrel which measured 0.075 inch (1.9 mm).

In our bulletcollection ofunsolved crime cases w9 haveno ,455Webley bullets; an easysearch. Ou .45 ACP bullet collection containsseven unsolved cases; a rather small collection. Sincethe .45 ACP test bullets has family characteristicsofan undersizedbullet, etc. and all rhe bullets in the unsolvedcrime collectionhas distinctive land impressionsthis searchwas also easy.

On the cartridges,another interesting phenomena was observed.All the ,45 ACP canridgeshave a distinctive firing pin drag mark on them but weak vertical breechfacetraces, the .455 cartridges haveno fuing pin drag mark ard haveclear distinct vertical breechfacetraces. Reasonscould be attributeddue to the differencesin materials,dimensions and pressures,In additionthe .455 Webley testammuition headstampis "...41...";dated to approximatelyfifty five yearsago, ln our carridge casecoilection ofunsolved crime cases we haveno .455Webley cartridges; an easysearch, Our .45 ACP canridge collectioncontains eleven unsolved cases, a rather small collectionand none comparedto the testshots. Sunimary:

All possibletypes of firearm and ammunitionalterations exist in the world of forensic science, and everyexaniner shouldbe awareofit. This casereport sharesour methodologyin handtingsuch a case,

Acknowledgment: The author wishes to thad( Major Howard Silverwater,Weapons ldentification Laboratory, for his help in writing this casereport. Photograph no. 1: colt Model 1911,semi automatic pistor, chambered for caliber,455 webrey Automtic, the serialnumber could not be restored.

Photographrc. 2: Homenudeext.actor with longerextractor hook (/op). O ginalextractor fiom .45ACp Colt Model l9l1At (bofto,r1). Photographno. 3: .455Webley Autonntic cartridge (,'igrl) .45ACP cartridge(/e/).

Table no. 1: Technical and Ballistic Data Caliber.455 Weblev Automatic Calib€r.45 ACP BulletDiameter 0.4s2"- 0.455"(11.48-l1.56) 0.438"- 0.451"O t.l2-1t.45) Casediameter - neck 0.4'71"- 0.416" fi 1.96-12.09)0.466"- 0.474"(11.83-12.04) - head 0.470"- o.4'7'7"(11.94-12.1 | ) 0.46a"- 0.476"(11.88-12.09) -flm 0.499"- 0.504"(l:.67- 12.80) 0.466"- 0.480" (l1.83-12.19) Caselensth 0,908"- 0.930" (23.06-23.62) 0.884"- 0.906"(22.4s-23.01) Mulzle velocity 740 ft. persec. 850ft. per sec. (5" barel) (225meter per sec.) (259meter per sec,) 222 - 226 st. bdlet 230 sr. bullet