Gunsmithing M1903 Rear Sight Question

[tomcatfan]

So I recently picked up an M1903A3 from James River Armory and went out to sight it in today. It took me a little while to get the windage squared away but when I finally did, the rear sight was way to the left. I was just wondering, are these rear sights staked at all? Before I go and start beating this thing with a punch to move it, I just wanted to make sure it will actually move along the dove tail.

Also in talking to Mark at JRA, I was telling him about how my old M1903 (leaf sights) shoots way high at 100 yds and I needed a front sight blade to fix it, he mentioned he uses the highest front sight blade he can get on his builds. Well even with the highest front sight blade, the rifle still shoots about 14" high at 100 yds. It looks like I need to look into the custom front sight post route as I suck as holding off target and shooting for groups.

 

[Dan M]

Everything depends on how James River put it together. Remington produced 03A3s has the rear sight base retained by a set screw early on, and then later retained by staking only, after targeting... Smith Corona used a stake and a set screw. Who knows what JRA did... there is no witness mark on the sight base in your photo... I doubt JRA targeted the rifle.

Looking at your photo, your sight base is already favored left.

As to your M1903, were you trying to shoot with the battle sight (leaf folded down)? That would explain why it shot high... the battle sight is calibrated for poi at 547 yards. The elevation scale on the M1905 rear sight on the M1903 should be fairly close with the aperture or using the field of view (looks like a Christmas tree).

 

[tomcatfan]

Yea with the M1903 I was shooting with the battle sight down. Next time I take it out I will put the sight up and shoot through the aperture.

I guess I will just have to give James River an email to ask what they did to put the rear sight on.

 

[Dan M]

Just an FYI, the sight is about as far left as it will go without starting to expose the right side of the dovetail...you might be able to get away with a little more, but you are close. It is apparent that JRA installed rear sights that were never previously installed on a rifle... it could be a nos military or a replica... can't tell from the photo.

When the rifle was targeted, the rear sight and receiver received a witness mark noting the position of the sight.

Your windage is one moa per windage click. Your elevation is based on the M2 Caliber .30 cartridge, and is a close approximation in yards.

PS, you should be able to look through the hole in the sight and see the staking if it is present.

 

[tomcatfan]

Dan, thanks for the pics, that is very helpful. I will look into that when I get home. But something I was thinking about last night. It looks to correct for elevation I need a new front sight post. I understand that would be alot easier. But rather than putting a new front sight post in to correct for it shooting 14 moa high and having a crazy high front sight post, couldn't I mill down the bottom of the rear sight and cut the dove tail deeper, effectively lowering the rear sight a little more? I'm not sure how much metal there is in the rear sight to play with, but I can't imagine how high my front sight needs to be to correct for 14 moa.

 

[Dan M]

That has been done before... I own more 1903s than I care to admit, and one had the rear sight notch filed down.

You can also get a replica USMC front sight blade... I bought one from S&S Firearms in NY for use in one of my shooter 1903s.

The USMC front sight is .075" taller than a standard front sight and is 0.1" wide... the USMC also used a 0.1" aperture as well. That would bring the zero down to 200 yards when using the battle sight with the leaf in the down position.

The 03A3 was targeted and the front sight could be changed to achieve a zero... there were 5 front sights available to do this, marked on the side of the blade with the letter A through E:

Front sight height
A .537
B .522
C .507
D .492
E .477

Glad to help Brother

 

[tomcatfan]

The 03A3 was targeted and the front sight could be changed to achieve a zero... there were 5 front sights available to do this, marked on the side of the blade with the letter A through E:

Front sight height
A .537
B .522
C .507
D .492
E .477

Glad to help Brother

I saw that on other forums. I measured my front sight post and it measures out as an A at 0.537". Its the tallest they make and it still shoots about 14 moa high. I was also reading that each transition from A-E equals roughly 2 moa. With that being said, each transition for the most part is 0.015" difference. So based on the math if I need 14 moa, I need a front sight post that is 0.642" tall. That seems really high to me. Thats why I was thinking I could trim my rear sight and lower it by 0.105". I just need to check and see if there is enough metal there to play with.

Has anyone else done something like this in the past?

 

[Dan M]

I have seen front sights built up with a braising rod and filed to achieve poa/poi, but that can be labor intensive. Deepening the battle sight notch and playing with the front sight height is more work than I care to do... You would literally be taking one pass of a file and shooting to check correction.

I don't use the battle sight, I just use the aperture or the open sight in the field of view.

 

[pmclaine]

On the M1903 the front sight blades were filed to register the gun to the leaf. It was really hit or miss (no pun intended). I have 2 1903s and neither really works with the marks on the sight leaf.

An indispensable tool for shooting a 1903 is an PJ Ohare sight micrometer. Creedmoor Sports sells a replica under the Ray Vin name (SBS sales makes it). This tool will allow you to dial MOA and record your settings for various ranges. The Creedmoor version is +/- $140, originals PJ Ohare micrometers can be found and sometimes you will get one for $125, usually they will be more.

If you want to seriously shoot an 03 you want a sight micrometer.

Also google Bill Bentz. He makes some nice USMC replica sight blades and aperatures. A lot of shooters like that sight system. I find the original blade more accurate.

 

[tomcatfan]

I've heard of Bill Bentz and was considering contacting him for my sight options. Also just to clarify, I'm not really going to mess with my M1903, I've just accepted it shoots high and since it is almost 100 years old, I'm fine not shooting it that much anyway. Besides I'm not that accurate with that open leaf sight anyway. I prefer peep sights. Now the 1903A3 I bought to shoot. And with the peep sight, I would like to get that sighted in if I can. I only have access to a 100 yd range unless I want to drive for 3 hours so thats the range I'm working with. My 1903a3 is the one I'm talking about shooting 14" high even with the rear sight bottomed out and an A front sight blade.

 

[Dan M]

I have more than 20 M1903 rifles and have owned a few 03A3s... right now I only own one 03A3 as an example. My M1903s shoot spot on, I have never had an 03A3 that shot POA/POI without putting on some elevation and dialing some amount of windage...and I have been collecting and shooting them for about 35 years. The Remington 03A3 in my collection is an original early 4 groove, and shoots closest to POA. You can see from the photos the windage needed for 100 yards... I shoot the elevation at 200 yards, I had to push the aperture up to show the stake marks in the sight base.

Make sure you are shooting M2 ball or a hand load to M2 specs.

I have always been frustrated with 03A3s and having difficulty with them shooting POA... I actually dislike them, but they are an important piece of US WW2 history and have a place in collections and at the range.