Are you talking about the hammer mounted firing pin? The 32 Hand Ejector, No Change or Model 1903 was in serial number range 1 - 19425. made in 1903 and 1904. The 32 HE, 1st Change started manufacture in 1904 with some design changes. So your revolver would have been manufactured most likely in 1904.

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Gary
SWCA 2515