Reference:6150: Difference between revisions

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The 6150-specific movement configuration is the absence of chronometer pass. The same A296 in the 6350 was fine-tuned and adjusted to chronometer standards, earning the OCC dial line. The 6150's A296 does not carry that adjustment.

~~The bumper-vs-~~full-rotor ~~question on~~ A296 ~~is unresolved across~~ the ~~published literature. Some Explorer references read A296 as~~ a bumper-~~style~~ automatic ~~that the~~ caliber 1030 ~~superseded;~~ the ~~watchdoctor.biz registry~~ and ~~Rolex Forums read A296~~ as ~~full-rotor. Both readings are on record~~; ~~the resolution sits with Colin A. White~~'s ''~~Vintage~~ Rolex ~~Field Manual'~~'.

A296 is a full-rotor uni-directional Perpetual, not a bumper. The architecture confusion that briefly attached to A296 traces to the bubble-back caseback geometry — the thicker autowind module the A-series carried, not a bumper rotor system — and to dealer copy that conflated mid-1950s automatic watchmaking generally with bumper-era movements. Rolex never produced a bumper caliber. The 1030 that succeeds A296 introduces bidirectional winding (the butterfly rotor) and a thinner module, which is what eliminates the bubble-back profile (Phillips Geneva Watch Auction FOUR lot 146 frames the A296→1030 swap explicitly as a thickness change; Wind Vintage / Eric Ku, ''How Rolex Became Rolex: The Automatic Perpetual Movement (Part 2)'' dates Rolex's first bidirectional winding to the 1030).

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 The 6150-specific movement configuration is the absence of chronometer pass. The same A296 in the 6350 was fine-tuned and adjusted to chronometer standards, earning the OCC dial line. The 6150's A296 does not carry that adjustment.
-The bumper-vs-full-rotor question on A296 is unresolved across the published literature. Some Explorer references read A296 as a bumper-style automatic that the caliber 1030 superseded; the watchdoctor.biz registry and Rolex Forums read A296 as full-rotor. Both readings are on record; the resolution sits with Colin A. White's ''Vintage Rolex Field Manual''.
+A296 is a full-rotor uni-directional Perpetual, not a bumper. The architecture confusion that briefly attached to A296 traces to the bubble-back caseback geometry — the thicker autowind module the A-series carried, not a bumper rotor system — and to dealer copy that conflated mid-1950s automatic watchmaking generally with bumper-era movements. Rolex never produced a bumper caliber. The 1030 that succeeds A296 introduces bidirectional winding (the butterfly rotor) and a thinner module, which is what eliminates the bubble-back profile (Phillips Geneva Watch Auction FOUR lot 146 frames the A296→1030 swap explicitly as a thickness change; Wind Vintage / Eric Ku, ''How Rolex Became Rolex: The Automatic Perpetual Movement (Part 2)'' dates Rolex's first bidirectional winding to the 1030).
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