My Type 38 Mukden rear sight?

Recently bought a Mukden Type 38 rifle. It is pretty much an unissued piece. Numbers match on reiceiver, bolt, and bayo lug. The rear sight has different 2 digits than rest, but is also as new. Sight has pyramid shaped aperature battle sight with straight bar sliding peep aperature. Max sight graduation is 2200 M. All other rear sights on Type 38 rifles I have seen have 2400 M maximum. Rifle is in the 1800 s/n range. Is this a charcteristic of a rifle towads the end of Type 38 run? When about was it made? Thanks for any input you folks may have on this.

Mukden Type 38's with serial numbers above 5064000 will have the pyramid shaped rear sight with elevation to 2200.

Thanks Aragorn243. Rifle has forged buttplate, like earlier production rifles. Maybe rear sight was changed out later? Rifle s/n 1875 sight parts maked 30, bolt and bayo lug are marked 875. "Mum" is sloppily filed off, rest of metal rates excellent, bore is perfect, no primer ring on bolt face, and still had arsenal grease in breech. Bought this rifle as a shooter. This is a nice solid rifle, very tight like a new rifle should be. Is now all cleaned and oiled, ready for the range-can't wait! Still scratching my head over the 5,000,000-5,065,000 range. Going by the chart in the "Markings on Japanese Arisaka Rifles..." 104,000 Type 38 rifles were made at Mukden, none after 1940. Is this correct?

Mukden serial numbers for the type 38 are:

1-38,000
5,000,000-5,065,000
and 65,000-79,000 which are sometimes misidentified due to characters resembling a "3" in front of the serial number

All were made between 1934 and 1940, 117,000 were made. All Mukden rifles have the same buttplate through the entire production run.

Mukden also produced the type 38 carbine serial numbers

1-2000
600,000-628,000
and series 6 28-000-43,000

For a total of 45,000

All data is from Japanese Rifles of World War II by Duncan O. McCollum