M1917 Ammo & Rear Sight

[Cosine26]

The question is-“For what ammunition is the M1917 sight calibrated?”
At the time the M1917 was developed from the P1913, the standard cartridge of the US Army was the Caliber .30 Ball Cartridge so I would believe that it would be safe to assume that the sight would be calibrated for this cartridge.

References to the Tables of Fire for the 30-06, the 30 M1 Ball, and the 30 M2 Ball would indicate that the difference at the usable ranges is not significantly different to the average soldier to warrant re-calibration of the rear sight. Since the M1917 was not designated as the service rifle but was declared to be “substitute standard”, I do not believe that the M1917 sight would be re-calibrated for any new cartridge. As a matter of fact, I do not believe that the M1903 rear sight was recalibrated when the 30 M1 Ball or the 30 M2 Ball ammo was introduced.

Here is an excerpt from the Field Manual for the M1917 at the time it was issued during WWI.

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FWIW