M1911 Vs. M1911A1

The Original M1911 went into production in late in 1911. In 1924 the pistol was given some upgrades based on feedback from World War I. These changes went into effect in 1924 and constitute the change from the model M1911 to the model M1911A1. The most common and easiest to identify changes have been detailed below. As a collector you must be able to spot these components as it will help you determine if an example is all correct or NOT! Some times field service and arsenal rebuilds will cause a M1911 to have M1911-A1 parts. This is not a bad thing if the gun has the proper rebuild marks, but anything non-factory original will reduce the value of the pistol (See arsenal rebuilds markings in the ID Pages section on this site).

M1911

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 M1911-A1
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  • Long Trigger

  • Short Spur on grip safety

  • Flat Main Spring Housing

  • Thin front sight

  • Small rear sight notch

  • Wood Double Diamond checkered grips

  • Serial Number Range 1-629,500

  • Short Trigger

  • Trigger Relief Cuts

  • Long Spur on grip safety

  • Sights updated

  • Wide front sight

  • Wide rear sight notch

  • Wood or Plastic full checkered grips

  • Serial Number Range 700,001-2,660,318
NOTE: During years when pistols were made in high volume, pistols were assembled by pulling parts out of assembly line parts bins.  As the inevitable manufacturing changes were approved and phased in,  there would sometimes be old and new parts mixed in the bins.  If the inventory control people were conscientious, by purging and rotating stock, a clean changeover point of old/new might be achieved.  However this sort of diligence and attention to detail was probably the exception rather than the rule.  Overlap of old/new features usually happened to some extent.  During years of relatively low production, parts might have been allowed to “run out,” before new type parts were added, and of course the diligence of the workmen would vary between manufacturers.  For example when Colt changed from checkered to serrated thumb safeties in 1945, there is observed overlap over a range of serial numbers.   Some pistols would have the checkered, then the serrated, and then the checkered could be found again on later examples.

Rev 1.0a