Before getting into the factual specifics of the various versions of the M3, it is worthwhile to spend a few moments discussing one of the major misconceptions that abounds about it. That is, that as Leica got more experience building them, the general quality of M3's improved. Except for the first few hundred, as the assembly line shook out, this is absolute nonsense and there is a hard rumor that the whole thing is attributable to a single camera salesman, years ago, who promoted the idea to encourage sales of the "newer and better" later M3's. There is an entire pricing hierarchy that prices 1,1XX.... over 1,0XX.... over 9XX.... etc. If you have a conversation with actual technicians who work on them, you would learn that there are no meaningful differences over its life except, perhaps for attention to such miniscule details as how flash wires are twisted and routed in the very early ones and the fact that during 1959, onsetting approximately with 954,XXX, there were a number of design issue change/improvements in the basic M3 body: The film advance/transport, shutter and the shutter brake system underwent a substantial revamping resulting in a much more durable body.

Other than those kinds of things, and other than such gross differentiable issues as the DS to SS conversion, the actual quality of M3's remained relatively constant over its life.

Production of the M3 onset in 1954 with serial number 700,000 and continued into 1966 generally ceasing after production of a total of almost a quarter of a million with number 1,164,865 (though a small number were produced later to fulfill contractual obligation with the German Army).

Improvements to the Leica line that the M3 pioneered comprise:

1. Arguably the most significant change was the introduction of the fast action bayonet mount replacing the tedious and slow SM of Leica's III series. Conversion mount rings permit the use of the older SM lenses.

2. The next most significant improvement was the replacement of the film advance knob with a film advance lever (early Double Stroke later replaced with a Single Stroke version after serial number 915,251). The Double Stroke version is regarded by many as more durable and there exist rumors that engineers at Leica initially worried that the more brutal action of a Single Stroke embodiment would result in torn film sprocket holes.

3. Next is the immensely improved, brilliant combined rangefinder/viewfinder with lens keyed parallax corrected bright line frames indicating the view of lenses chosen (50mm, 90mm or 135mm)

4. The M3 introduced, for Leica, a new single shutter speed dial but the earliest one preserved the legacy shutter speed progression of the SM III series two dial system. The new non spinning (during exposure) shutter speed dial permits the mounting of a coupled meter. Prior to serial number 854001 the shutter speed sequence followed the "legacy two dial" progression which changed to a more modern progression afterwards.



5. A hinged back door to facilitate loading of film and which resets the film counter when opened.

Variations:

The first 450 or so had a more crudely (sharply) curved shaped top plate (rangefinder enclosure)

Very early bodies had four additional screws (two front and two rear) securing the top plate

A small number of camera bodies were fabricated of German manufactured parts in Canada but not designated as such

The standard color was chrome; black (painted) was introduced at SN 959,401 in 1959; olive green (painted) were produced in batches for the German army

Early on the bayonet ring was secured to the body by four screws at the two, four, eight and ten o'clock positions respectively. Later a fifth screw was added at 12 o'clock with a Leica sealant which was intended only to be removed by a Leica authorized facility.

To give visual feedback as to the movement of the film on rewinding, the rewind knob is marked near it center. Early on the mark was a red slot, later a red dot and finally the mark was two red dots.

Strap lugs are triangular or teardrop shaped on earlier production and semicircular later.

Very early M3 bodies had a different body casting/film path appearance.

Film speeds increased over the life of the M3 and the reminder on the back changed

Annual production figures for the M3 are as follows:

1954 10,001 all chrome
1955 49,491 (incl. 540 Canadian) all chrome
1956 22,550 (incl. 990 Canadian) all chrome
1957 35,300 (incl. 1550 Canadian) chrome & 100 Grmn Olv
1958 8,500 (incl. 100 Canadian) all chrome
1959 22,972 (incl. 1150 Canadian) all chrome
1960 17,950 (incl. 1100 Canadian) all chrome
1961 13,901 (incl. 800 Canadian) chrome
1962 13,004 (incl. 400 Canadian) chrome & 2150 Grmn blk
1963 10,000 chrome
1964 5,900 (incl. 150 Canadian) chrome & 150 Grmn blk
1965 9,350 (incl. 200 Canadian) chrome & 150 Grmn blk
1966 4,905 (incl. 100 Canadian) chrome & 10 Grmn blk
1967 44 Olive

Sales data sources: Leica Germany/US of A; Leica Collector's Guide, Dennis Delaney

In all 226,178 Leica M3's are believed to have been produced, but the figures add up to that number due to statistical gathering deficiencies.