gnoahh, another review from 1912 gives these stats for the 22HP:

Bullet diameter: .228 in.
Diameter of barrel land to land: .219-.220 inch
Groove to groove width: .226 in
Depth of groove: .003 in
Width of groove: .065 in
Number of grooves: 6
Twist of rifling: 1 in 12 in


Townsend Whelen in his 1918 book, "The American Rifle: A Treatise, A Textbook And A Book Of Practical Information In The Use Of The Rifle", writes about the 22 Savage:
Diameter of bullet: .228 inch
Groove diameter of bore of rifle, about: .226 inch
Depth of grooves: .003 inch
Twist of rifling, one turn in: 12 inches


So it's not just Horace. Interesting numbers..

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