Can't tell you exactly, but just under 20,000 were manufactured from 1896 to 1903. Interpolation suggests yours may date to 1897. There is s/n between 2700 and 2800 that was shipped in early 1898.
Sort of feels to me that if you allow for increasing production, the 1899 guns would start with a number in the 7000-8000 range, but that's just an estimate.