1903 Springfield, Rear Leaf Sight Tube Problems

[Frost Cracked]

I recently purchased a 1903 from the EE on this sight. It came sporterised with a scope and boyds stock, no main issues there. The barrel on it had been replaced with a NOS barrel some point in the rifles life.

I managed to get together that parts that would be needed to restore the rifle, but in doing so have come into an issue. I purchased a repro rear-sight mount-tube, assuming it would fit fine. It does not, however. My gunsmith measured it and found it too tight to properly mount on the barrel.

My question is, why this might be? Is the barrel too big? Did later 1903's (A1, etc) have thicker barrels? Or is the repro mount too small? Unfortunately I do not have the rifle right now, but if someone has any ideas or suggestions I would appreciate it.

 

[purple]

I recently purchased a 1903 from the EE on this sight. It came sporterised with a scope and boyds stock, no main issues there. The barrel on it had been replaced with a NOS barrel some point in the rifles life.

I managed to get together that parts that would be needed to restore the rifle, but in doing so have come into an issue. I purchased a repro rear-sight mount-tube, assuming it would fit fine. It does not, however. My gunsmith measured it and found it too tight to properly mount on the barrel.

My question is, why this might be? Is the barrel too big? Did later 1903's (A1, etc) have thicker barrels? Or is the repro mount too small? Unfortunately I do not have the rifle right now, but if someone has any ideas or suggestions I would appreciate it.

I've never seen a repro rear sight sleeve but the original ones fit very tightly. I've installed a couple of them by using a hardwood block drilled to fit the barrel diameter. Put the block against the front face of the sleeve then get a piece of pipe that fits over the barrel and is long enough to drive in leaving a couple of inches clearance in front of the muzzle. Then get a piece of 2x4, put it on the front of the pipe and drive home with a 2 lb hammer.

Put the rear sight moveable base on the sleeve to avoid distorting the sleeve when hammering. It may be necessary to heat the sleeve to expand it somewhat.

 

[Frost Cracked]

We managed to get the front sight off, and tried it out as a test fit. The difference between the barrel at the back of the knox, and the mouth of the reciever end tube is around 400th of an inch. Could ite be possable that I may be dealing with a larger barrel?

 

[bearhunter]

1/400th???????????? Weird measurement. That would work out to .0025 inches. This would make a very good PRESS FIT, which is what is intended.

Freeze the barrel, put the sight base into boiling water and they should slip together with just a bit of resistance. You have to be quick though because the temperatures will soon become equal and the pieces will be literally welded together.

 

[Frost Cracked]

Heya,

I finally got it back from the smith now, and I'm taking a set of measurements with my micrometer, as it still doesn't seem to add up.

Barrel, at the knox, is 1.193 inches (give or take 0.0005 an inch), while the sight ring is around 1.136 inches at the receiver end.

The exit end of the sight ring is also smaller, than the barrel diameter to where it SHOULD bump up to. Thinking this barrel is bigger than a standard 1903....

 

[bearhunter]

The NOS bbl on your rifle sounds like it was for a 1903a3. It may require a bit of machining on the surfaces so the O3 sight will fit.

These parts need to fit tightly or they need to be cold soldered in place. Your smith should know that or have been able to find it out with very little effort.

I suggest you Google "fitting a rear sight base to a 1903 Springfield barrel"

I'm surprised your smith didn't do that or have the information handy. Not very professional or maybe he isn't into milsurps.

Do your due diligence then you know what questions to ask and either do it yourself or find a competent smith from someone here. So far your all over the place without any idea of what to do.

 

[rgg_7]

If it's been rebarrelled an A3 barrel was most likely used. A3 does not used the sight sleeve rather the rear sight is mounted on the rear of the receiver. Best to look for an 1903 A1 barrel. Maybe some body would trade with you. Ron

 

[Frost Cracked]

If it's been rebarrelled an A3 barrel was most likely used. A3 does not used the sight sleeve rather the rear sight is mounted on the rear of the receiver. Best to look for an 1903 A1 barrel. Maybe some body would trade with you. Ron

Thanks Ron, I figured that as much. When I got it I pieced together from the serial # that the receiver was WW1 design. It does not have the rear-sight mount that the A3 had. I knew when I got it, that it had been rebarreled but at the time was not aware the A3 barrel was actually thicker.

The gunsmith I go to is quite capable, and very professional. He's a retired machinist and knows his techniques, it's just military surplus rifles are not his interest.

At the moment I suppose I will have to see about either getting ahold of an A1 barrel... or having the A3 barrel turned down a bit at the knox, to fit the sight collar. I may go for the turning down, as it'll probably be the cheaper of the 2 options.

 

[bearhunter]

Thanks Ron, I figured that as much. When I got it I pieced together from the serial # that the receiver was WW1 design. It does not have the rear-sight mount that the A3 had. I knew when I got it, that it had been rebarreled but at the time was not aware the A3 barrel was actually thicker.

The gunsmith I go to is quite capable, and very professional. He's a retired machinist and knows his techniques, it's just military surplus rifles are not his interest.

At the moment I suppose I will have to see about either getting ahold of an A1 barrel... or having the A3 barrel turned down a bit at the knox, to fit the sight collar. I may go for the turning down, as it'll probably be the cheaper of the 2 options.

Aftermarket Criterion barrels are available for your rifle. They're pretty decent repros but of course won't have the dates you require. Here's the big question. Why are you re militarizing this rifle??? Is the receiver drilled and tapped???

If the receiver is drilled and tapped it likely isn't worth spending a lot of money on the project to make it correct because it never will be.

As for turning the barrel to accept the sight base there is a bit more to it than that. From the sounds of it your friend is up to the job. The sight base has to be indexed so when the rear sight assembly is installed it is at top dead center and aligned properly with the front sight. This can be tricky if it isn't done right. Also, do you have the proper stock??? Luckily the O3A3 stock will fit all models but the top wood and ferrules are different.

There are some very good books on this subject, showing parts and giving excellent instructions on how these rifles should be put together and why certain things must be done to make sure they shoot well.

If you have to pay your smith to educate himself to a project he really has little or no interest in, you are likely way further ahead doing the work yourself. All it takes is time and patience for most of it, along with some very basic tools. About the only thing you might need the smith to do is turn down the barrel diameter at the proper location to a diameter that ensures a press fit and fly at it.

Going by guess and by golly with information from us can be extremely confusing. Especially since you aren't familiar with the terms and nomenclature. Get a book. They can be found online and even in some local gunshops. Del Selin in Vernon BC has a rack full of such volumes. I don't know where you live but there are likely book vendors there as well.

The little books I'm talking about cost under $20. There are also sites on the internet devoted to such projects and are chock full of pictures and descriptions. Good Luck.

 

[purple]

Tell us what the markings are on the top of the barrel behind the front sight. That will ID whether or not you have an 03 or 03A3 barrel. I've installed a military 03 rear sight sleeve on both 03 and 03A3 barrels without any barrel alteration. A repro rear sight sleeve is an unknown factor here.

 

[Frost Cracked]

Tell us what the markings are on the top of the barrel behind the front sight. That will ID whether or not you have an 03 or 03A3 barrel. I've installed a military 03 rear sight sleeve on both 03 and 03A3 barrels without any barrel alteration. A repro rear sight sleeve is an unknown factor here.

The markings say:

R A
(Flaming Bomb, barrel on fire, or perhaps an onion stamp?)
9 - 43


Here's a picture I snagged. Not my barrel, but the same sort of thing.

 

[purple]

The markings say:

R A
(Flaming Bomb, barrel on fire, or perhaps an onion stamp?)
9 - 43


Here's a picture I snagged. Not my barrel, but the same sort of thing.

"RA" over 9-43 indicates that it is an 03A3 replacement barrel made by Remington in Sept 1943. These were made with 2 groove rifling, but SARCO re-worked quite a few of them 25 yrs ago to make them a 4 groove. SARCO also fitted many of them with military 03 rear sight sleeves to adapt them for use on 03s. Strange, but true, and they shoot well.