1903 Rear Sight Aperatures

[pmclaine]

Looking at various 03 rear sight slides I am amazed how the standardized military has such a range of diameters for the rear sight aperature. You don't see this with the systems that followed in the wake of the 03 (save for perhaps National Match specific rifles or the day/night flip sight on the AR series).

Did the military ever put out documents explaing the variety of aperatures?

I currently have a Bill Bentz repro #10 USMC sight set on my 03A1. I have a theory that the Marine Corps sight is the best system for battlefield use (large aperature and large front sight post are easier to align under stress and during rapid fire also more visible in poor light conditions) but the smaller aperature and fine front sight blade make for a better precision shot system.

I bought another rear sight with a #4 slide and am collecting parts to build/install a fine front sight blade.

Anyone already played with the two sight types (#10 USMC versus Armory issue) and have opinions on which is the best for use in CMP/range applications?

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[DeputyBill]

PMcLaine,
I can't answer your initial question; I can just share a little of what's been shared with me on the subject. As I recall being told, spare apertures were included in crates of rifles and, for reasons we can only imagine today, the smallest (& most precise) No. 4s were not typically used on combat-ready rifles.
I had never considered the distinction, or noticed that mine had a "4" stamped on the reverse, until John Beard brought it to my attention a few years ago.
I had always thought my rifle was just your typical "good shooter" and have enjoyed taking it to the range since I was a boy, with my dad who bought it in the 1950s.
I agree with your observation, though, that while the No. 4 is the most precise size, I'd opt for a larger aperture in low light or in an adrenaline-charged combat situation. Since the M1903 was first & foremost a combat rifle, that would explain the relative scarcity of No. 4 apertures, today.
Kind regards

[RCS]

Attachment 21434 I still like the #8 on the right side of this photo. With the number 8 you still have the u notch while the #10 is without this u notch

[RBruce]

Certain size rear apertures are plentiful, others are scarce. Find a common size and drill to what ever size you want. The military did this, and renumbered the aperture.

[pmclaine]

Wow resurrection. I ended up changing my #10 to a 5 or something, the exact size escapes me right now. I did a test between #10 sights and the standard sight and found my accuracy improved with the standard sight. #10's are great for low light/combat but the standard sights are better for targets in my case. I posted a comparison of my results with a bunch of pictures on Jouster. Do a post search for my name or a thread something like USMC sights vs standard sights if you are interested in my comparison.