Before you do anything permanent, clean, clean, and clean the chamber again. Scrub and scrub some more. Stuff some patches soaked in kerosene into the chamber and let it soak, and scrub again. If your rifle has sat for that long, dried oil and grease will affect the reading on your gauge. How do I know? Same thing happened to me. I bought a beautiful Remington 1903. It had a sedgly replacement barrel on it. After thorough cleaning, wouldn't close on a go gauge. I thought short chambered just like others have said. So I chased with a reamer. I pulled out after a couple gentle turns followed by just one good one, since I new I would just need to kiss it if at all to get the bolt to drop. The swarf that came out had no metal on it...just crusty dark brown gunk (not orange/red like rust would be). Closed on the go gauge immediately.
If you've ever disassembled, say a winchester 97 or worse a model 12, which most owners in it's history are too timid to disassemble and really clean, you'll know that decades old grease or oil will cement with dust, fouling, etc. and create a near impenetrable mess. I had a model 12 once that not even a week long soak in kerosene would lift out all the cement from behind the bolt. As a last resort...boiling in water will lift it out, or make it brittle enough to come off with a good scrubbing.
EDIT: if you indeed do have a short chamber, the bolt will not close at all on round (remove all fire control before checking). If it's just old and dirty, the bolt will likely gently squeeze shut on some rounds. Short chambered barrels are like 0.010 short or sometimes more. I've fit some NOS 1903 barrels still in the grease and this was the case. If it's short, your bolt won't come anywhere near closing. You wouldn't even be able to pound it shut with a hammer on round. Post a picture of where your bolt is falling.
From this and other sources I agree that a bit of reaming should help, but I have never reamed a gun and do not plan to start now. Plus, I think I want a Hatcher hole drilled and the extractor to have a hole drilled to match the gas escape hole on the right side of the receiver just like my other 1903 has.
There is a reamer you can get called a pull through finish reamer get that has a rod attached that runs through the end of the barrel I've seen used. Seemed like a relatively simple job. They're not too expensive and can be resold when finished. Cheaper than a gunsmith. Or just a good excuse to get more tools.
This guy uses one at 21:45:
If you do end up needing it, you can rent reamers affordably from https://4drentals.com. I have used them several times before.
A pull through reamer would work, but is really designed for actions like m1 garand or carbine where the rear is closed. You can rent a t-handle from 4d with the reamer for your 1903. The first time I reamed a chamber I wrapped vinyl tape around the shank of the handle to help keep it centered in the action. I quickly learned it wasn't needed. If you are patient and go slow, things will turn out perfect. It is very very easy to do. Larry mr. Potterfield shows off how easy it is... he reams at 3:20.
A pull through reamer would work, but is really designed for actions like m1 garand or carbine where the rear is closed. You can rent a t-handle from 4d with the reamer for your 1903. The first time I reamed a chamber I wrapped vinyl tape around the shank of the handle to help keep it centered in the action. I quickly learned it wasn't needed. If you are patient and go slow, things will turn out perfect. It is very very easy to do. Larry mr. Potterfield shows off how easy it is... he reams at 3:20.
Huh. Thanks. Never seen finish reaming with a t-handle. Or maybe I forgot? Had it in my head the barrel was to be pulled and finished in a lathe but the pull through reamer was a work around. Probably gotten that conflated with finishing barrels like for ar15s. That'd be why I keep my books and read again before starting a new project.
Jim, I defer to your broader experience. I speak only of the 1903, and frankly, to the best of my knowledge, the M1 Carbine, Garand, M1918, M14 and pretty much any other smokeless powder Military long arm from any primary combatant of conflicts involving the U.S. I have little practical experience with "modern" bolt action rifles.
I do have a question of the practice though. Im unsure of the typical barrel thread pitch, but unless the pitch is super-fine it would not take much rotation to set the barrel head back quite a bit. Considering the very small difference between "GO" and "Field" gage sizes Im surprised there are chambers cut so short as to require more than just a little headspace reaming. When I cut a short chambered 1903 barrel I have to be VERY careful not to take too much off. I confess with some chagrin that Ive ruined a number of barrels when I cut the chamber too deep with what seemed to be just a turn or two of the reamer. Is rotational alignment not required in such barrel/receiver designs that you are familiar with? If there is no barrel shoulder to compress against the receiver face how can the correct torque be set?
Square threads on the 1903, 10 per inch I think, with grooves at 0.051 wide. Yes. google doesn't lie
Originally Posted by 1903Collector
When I cut a short chambered 1903 barrel I have to be VERY careful not to take too much off.
even more careful on an old barrel that appears to be short. Even just a little leftover jagged edges from surface rust on the chamber's shoulder can throw off your go gauge. On new short chambered barrels, it usually takes me 5-20 turns. As such, I make one turn without any downward pressure just to clean out any possible edges left by the rougher, then I take it 2-3 turns at a time with very very light pressure. There is no reason to press down noticeably when finish reaming by hand. Use plenty of cutting oil, clean everything out every 2-3 turns when you check your progress.
setting a 1903 barrel back would require a full turn taken off the shoulder (so ~0.100), and then the same amount taken off the breech face, extractor groove deepened, etc.
There should be a shoulder. I can't picture a military barrel without one, nor a civilian barrel presently. If no shoulder then it would turn against a ring inside the receiver, or like the Lee Enfield, both.
Originally Posted by 1903Collector
it would not take much rotation to set the barrel head back quite a bit
When you talk about setback, you talk about it in a complete rotation, usually. If it were certain civilian rifles with rapid taper and unmarked barrels you could get away with less. It takes a minute to figure out how much to machine off the shoulder to give one turn to TDC.
Originally Posted by 1903Collector
Ive ruined a number of barrels when I cut the chamber too deep
You wouldn't be alone. Very, very careful. Last M1 rifle I did was a .308 barrel and it took so long with a breech end ream...but turned out perfect and tight.
PM
Originally Posted by RDG
