A3O3 Sight Need Help

[Boyscout]

I have a "sporterized" A3 O3 that I would like to return to military condition if I know it will shoot well. Other than some crud in the chamber which I can easily clean it appears to be in good shape. However, I do not understand the sight at all. The notch sights are unusable for me but the aperature sight appears to be good for my purposes. The windage adjustments are in good working order and look to be capable of very fine adjustments. Can anyone explain what I have here?

8068780688

[Dale in Louisiana]

Here's a thread off the CMP forum that explains it quite well: http://forums.thecmp.org/showthread.php?t=64134

These sights are quite accurate.


Dale in Louisiana

[Larry Gibson]

BTW; you have a M1903 or a M1903A1. Only difference being a C stock on the 'A1.

The M190A3 has an aperture rear sight mounted on the rear receiver ring.

Larry Gibson

[Boyscout]

Serial number is 3328281, US Remington 1903. It has pins through the stock instead of cross bolts and the handle is swept back. The manufacturer is Remington.

[Scharfschuetze]

Remington made two iterations of the 1903 before moving on to the 1903A3 to simplify production.

First iteration was virtually a duplicate of the original 1903 while the second started showing shortcuts in detail. It all ended up with the 1903A3 and as Larry points out above, with an aperture sight as well as stamped steel accouterments.

[Boyscout]

Thanks for the info. At what range, is the aperature registered for when the ladder is up and the aperature is visible on this particular sight? Also, What is the purpose of the triangular opening on the sight?

[Calamity Jake]

There are 4 sighting areas on the 03 rear sight, three notches and an aperture. Use the sight in its elevated condition
if your are using low volicity loads then use the aperture or the notch just above it, the third one up on top of the elevation
adjuster will be to high.
With the sight in the lowered position the notch is calibrated for 200 meters with ball ammo.

[Scharfschuetze]

Boyscout,

Assuming that you have the correct height front sight for a good zero with the ladder up, the index line on both sides of the aperture, base of the triangle (alternate rear sighting notch) as well as the top of the slide on the primary rear sighting notch will give you the range when lined up with the range figures on the slide. Unit armorers were issued with different height front sights to zero up the elevations shown on the ladder/slide.

I believe that these sights are calibrated for M1 Ball ammo which was the standard issue in WWI. It had a 174 grain (appx.) spitzer boat-tail bullet that far outranged the M2 Ball ammo of WWII and the Korean War. For those wanting to duplicate the 30/06 M1 Ball ammo, you can use either M72 Match ammo (pretty scarce) or use the 175 grain Sierra MK with IMR 4895 loaded to about 2600 fps.

From your photo, and if you have the proper height front sight for a good zero with M1 Ball, then your primary rear notch is set (best I can tell from the photo) for 1500 yards, your alternate notch for 700 yards and your aperture for about 200 yards.

[Boyscout]

I will probably start with 48 gn IMR 4320 behind 165 gn Sierra Match Kings. A gentleman at church gave me 7 1/2 pounds of the IMR 4320 and 1000 bullets. I will also be using Accur 5744 and a Lee C309-170FP which has shot well out of my Marlin XL7 30-06.

I post some photos after my next trip to the range. Thanks for all of the help.

[Bob S]

The sight ladder was recalibrated in 1906 from the original M1903 Ball ammunition (220 grain RN, 2200 fps) to the M1906 Ball cartridge, 150 grain flat base at 2700 fps. The sight was not changed when the M1 ball cartridge was adopted ... partly because Springfield was planning on replacing the ladder with a receiver sight and was actively testing sights, and partly because at usual rifle engagement ranges, it didn't make much difference. When the M2 ball cartridge was adopted, the sight was once again "correct". Saved by the bell ;)

The two horizontal lines on the sides of the aperture are range pointers. With a properly targeted rifle, using M1906 or M2 ball ammunition or equivalant, set the lines on the desired range and you should be close to point of aim (POA) = point of impact (POI) at that range. Most target shooters use(d) a sight micrometer to set the elevation. This is much more precise and repeatable than the range markings, the range markings are then used only as a sanity check. An excellent reproduction of the old O'Hare micrometer was made by Ray Brandes until a few years ago. Although Ray has retired, I believe his Ray-Vin micrometer is still being made. IMHO, This is a "must have" accessory for shooting the '03.

The hash marks, or "points", on the "wind gauge" are equivalent to 4 minutes of angle. One full rotation of the windage knob moves the base 4 points, or 16 minutes of angle. In order the move the sight one MOA (which is about the maximum usable level of adjustment for any sort of "precision" target shooting), you need to be able to turn the windage knob 1/16 of a turn reliably. This is more easily accomplished if you put four dots of paint on the knob spaced on the quadrants; then you just need to estimate 1/4 of that distance. Most of these old '03's have a lot of backlash in the windage screws. Fixing or minimizing that is a subject for another post, but you can minimize the effects by ending every windage change by moving the sight to the right. Example, if you need to make a change of two minutes left, move the sight four minutes to the left, and come back to the right two minutes.

Have fun with your new toy. They are great cast bullet shooters. :)

Resp'y,
Bob S.


Resp'y,
BobS.

[Scharfschuetze]

When the M2 ball cartridge was adopted, the sight was once again "correct". Saved by the bell ;).

Isn't that a hoot! Great info.

[Lance Boyle]

Why does 540 yards ring a bell for the battle sight setting with the ladder folded flat on the barrel? A ridiculously far setting for a BZ

[Dale in Louisiana]

Why does 540 yards ring a bell for the battle sight setting with the ladder folded flat on the barrel? A ridiculously far setting for a BZ
At half that range, you aimed for the guy's feet, hit him in the belly. At closer range, who cares? You're gonna bayonet the dude anyway.

dale in Louisiana

[Scharfschuetze]

Lance,

Battle sight zero gave the infantryman the best trajectory to hit a standing man between the knees and the shoulders as I recall. For a Cavalry target the Battle Sight Zero was further.

[Bob S]

Why does 540 yards ring a bell for the battle sight setting with the ladder folded flat on the barrel? A ridiculously far setting for a BZ

The battle sight with the original M1903 Ball cartridge was 400 yards. That was the "norm" in those days ... most late 19th century Mausers have a 400 meter battle sight zero.

Nothing about the battle sight was changed when the M1906 Ball cartridge was adopted: only the markings on the ladder were changed. The slide cap remained the same. So for the lighter faster spitzer bullet, 547 yards was "watcha got". Nobody ever saw fit to change the slide cap for a more reasonable battle sight range with the new cartridge. That made it interesting when we HAD to use the battle sight for all rapid fire strings in the NMC. For 200 yards, a frame hold usually worked OK.

The Marine Corps sight system that was in limited use following WWI gave a more reasonable battle zero of about 250 yards. When I first started HP in 1965, I found that substituting the higher 03A3 sight blade for the short 03 blade gave a battle sight zero of just about 200 yards, which was perfect for the 200 yard RF on the old Able target (5V). The 03 was of course not the official Service Rifle for the NMC after 1940, but the Old Bird who ran our local matches still made us young college kids who were shooting 03's conform to the 1935 Rules!!


Resp'y,
Bob S.