NRA Sporter front sight base distance

[Willgaga]

Should have titled this “Scope Base Distance” - apologies

From what I have read in Brophy, it seems that the most common distance between the sight blocks on a NRA sporter .30 cal 1903 was 7 3/16 or 7.2”. This would give an adjustment of .25” per click on a Lyman 5a. I also know the NRA sporter could be ordered drilled and tapped for a scope. Question is whether it is possible it could have been ordered drilled and tapped for 6” centers? In reading the book for the Lyman 5a it gives adjustment instructions for both 6” and 7.2” bases.

Would 6” ever be a preferred option on a NRA sporter or would you only do 6” where you had no other choice due to the characteristics of the rifle itself?

Thanks much,
Will

Information

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[cplstevennorton]

I answered much more in depth on the CMP forum. But I don't think SA had much to do with the 6'' spacing at all. It seemed to be popular in the commercial market, but not in use by the military.

I do not know of any instances of SA drilling any M1903's with 6'' spacing. The only one's I can track for the military were drilled by WRA and the Army called the spacing too fragile.

[ArtPahl]

I don't know if this will help or not, but I measured the distance between the center to center of where the scope blocks would have been (my NRA sporter no longer has scope blocks) and I got 6 1/2".

[Willgaga]

Good to know. Do you happen to know if the holes were factory drilled or done later?

Thanks much,
Will

[ArtPahl]

Will,

According to a member here, my rifle was origionally purchased May 24, 1924. I have owned it for less than a year so anything I would say regarding when it was d&t'ed would be a guess. I can say it's a professional looking job for what that's worth.