1903-A3 GI Barrel throat length

W

WyndoCleaner

New member
Hey again, all! You might remember me when I asked about a Criterion barrel vs. a GI barrel for a 1903-A3.

I haven't gotten a Criterion barrel yet, but I do have some questions about the GI barrel.
On some Barnes TSX 168gr. hunting bullets, I have to seat the bullet 0.2" out more than what Barnes recommends so that it's 0.5" from the lands of my '03A3 from 1943. That puts the cartridge OAL at 3.414". I've heard that the 1903A3 throat is usually pretty long. The problem with loading the bullets that long is that they don't fit in the magazine. I haven't measured the diameter of the chamber, so I'm not sure if it's throat erosion or what.

I haven't directly measure the throat, and I doubt I have the tools to do so. Is there any possible way to shorten the throat so that the bullet won't have to be so far out of the case to reach the lands?
It would probably be simpler to just buy that Criterion, but it would be better if I could fix the barrel I have.
 
Yes, I have shot it. I'm not sure why you're asking that. I can usually get 1.5-2" groups at 100 yards with a 4x scope, using Hornady 168gr BTHP with H4350. I don't quite remember how many grains of powder, but it's pretty much minimum, as much of the powder didn't burn when I was building up a load. There was hardly any increase to recoil or velocity, and the point of impact with a higher charge.
 
Is there any possible way to shorten the throat so that the bullet won't have to be so far out of the case to reach the lands?
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No, you would need to add metal, and that is not practical.

You could have a smith remove your barrel and cut off an inch or so from the muzzle end, then rethead, reinstall and re-chamber it, but that will likely cost as much as your new Criterion.
 
Oh and:
I haven't directly measure the throat, and I doubt I have the tools to do so.
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If you reload and own a hacksaw you have the tools to measure the throat.

Size a case, then cut a slot from the case mouth down to the shoulder, and by hand, seat the bullet in the cut case just enough so it won't fall out. This should hold the bullet with enough tension that it won't move but not tight enough that chambering it in the rifle, the contact with the rifling will push the bullet into the case.

Chamber your test round and measure the OAL. Do this a few times, to make sure your measurements are consistent. You now have the distance to the rifling, today.

This will change as you fire the rifle, as the throat erodes, but you will at least know at this moment, this is where the rifling starts.
 
I haven't directly measure the throat, and I doubt I have the tools to do so. Is there any possible way to shorten the throat so that the bullet won't have to be so far out of the case to reach the lands?
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Yes, if that is what you want to do.

If you really want to shorten the throat. A gunsmith can machine the barrel's shoulder forwards (towards the muzzle), cut threads then re-cut the chamber.
As the new chamber will meet "fresh" rifling; usually this is done to get rid of throat erosion and save an expensive barrel. One of my bench rifle's barrel is shorter now than when I bought it. :D

The shoulder is where the barrel touches the receiver.
 
You're over thinking the whole thing. Every rifle chamber is slightly different and every rifle prefers a particular distance from the lands.
More importantly, a Barnes TSX and every other hunting bullet doesn't need that level of measurement. It's far more important for a hunting load to be consistent in its accuracy.
To find the max OAL for your rifle, put a bullet loosely in a case(no dies), long(over 3.340"), chamber it. The bullet should get pushed into the case mouth and be sitting right on the lands. Reduce the OAL from there.
However, 0.5" is 1/2". Distance from the lands is measured in thousands of an inch. And every rifle is different.
Throats get checked for erosion with a gauge. It's not actually measured. The CMP will sell you a Badger Ordnance throat erosion gauge for $62. Tools ain't cheap. Says for M1 Rifle, but it's the same thing.
"...loading the bullets that long is that they don't fit in the magazine..." .30 AP and its 168 grain bullet were 3.340" long. 3.314" should fit in the mag of an '03A3. Solid copper bullets are longer than their lead cored cousins, but OAL is OAL.
 
" I have to seat the bullet 0.2" out more than what Barnes recommends so that it's 0.5" from the lands of my '03A3 from 1943. That puts the cartridge OAL at 3.414"
"I haven't directly measure the throat,"

If you haven't "measured the throat" how do you know that your 3.414 OAL load is still 0.5" from the lands. That would be extreme and would likely affect accuracy.
As far as the statement about the 03A3 having a long throat, I've never given it any consideration. One of the most accurate 30/06 rifles I own is an 03A3 with the original barrel. No special ammo required, just load the Remington 150 grain CoreLokts and shoot.
 
The 03's have 10 per inch shank treads. To get the front sight lined up which shortening the shank means you're going to have to it 1/10 of an in at a time.

Doing that is going to prevent the barrel from fitting the stock unless you're going the bubba route, adding another stock. If you're going to do that you might aw well forget the 03 barrels and just add another barrel.

There is a better simpler way to meet you goal. If your bullet wont shoot in your gun to suit you, because of the length or what other reason,

FIND ANOTHER BULLET.

The '03 action is one of the most accurate actions you'll find. That's why it was chosen for the Mann Device (device used to check accuracy of military ammo)

As an "arms room" gun, or as issued, meaning not a match rifle the '03s are the most accurate military rifle made, that includes todays modern military rifles.

You first need to determine what you want out of the rifle. Is it a surplus military shooter or some custom bubba gun. You are unlimited in what you want to do with the bubba gun, but limited if its an unmodified as issued.

Either way I would start looking at different bullets. If you want a target rifle, such as HP or CMP games a 3.5 MOA rifle will clean the targets. If you want a hunting rifle, the 1.5-2 MOA load will be good for the 10 in. vital are of a deer to 500 yards.

But again look at different bullets. In the 20-30s Springfields dominated target shooting. Different ammo was tried. Here is a chart showing the accuracy of a heavy match barrel shooting different bullets at 200 yards.

Take a gander at Bullet #4. That appears to be about a .5 MOA load. the 110 gr bullet would have to be short in .30 cal. to get it loaded to get close to the start of the rifling it wont be in the neck.

Maybe I'm reading this wrong. Why is it necessary to get the bullet that close to the rifling. Some bullets may need this, some don't.

1.5 - 2 MOA seems like a large group when you look at all the sub-minute groups you see on the internet. It would clean a NRA HP target. Problem being the limiting factor is the shooter.

When I built my M1903A4 rifle or the CMPs Vintage sniper match, I bought an un-issued 1943 barrel. I believe those were the barrels used on the original 'A4s. Got some sighters and then won a bronze metal at my first match.

Since then I've been having scope problems and screwed up my last two matches, but that's me. Not the rifle, it still shoots. I have no idea what it does for groups at 100 yards because I don't shoot groups at 100 yards. I shoot that gun at 300 and 600 for score. Again my problem is glass, I need to get that figured out. Right now I can shoot my A3 better at 600 then my A4.

But first you need to find a bullet your gun likes. First thing I would do is dump the 4350 powder and try 4064 or 4895, then start shopping for bullets.

But again I may be miss reading you goal. I just don't believe the '03 needs a bullet stuck that far out of the case. Then move to 600 and see what your gun will really do.

This is a 600 group out of a brand new barrel on a new put together Garand using HXP Greek Surplus M-2 ball. If I came up 2 MOA and right 1 I probably could of cleaned the target. This was slung prone, not from a bench.

IMG_1068.JPG
 
Ok, the methods you guys mentioned for measuring is what I did. I actually got a kit with a 30-06 case with a hole drilled in the end with threads, and all you do is screw a rod in, stick a bullet in it, put it in the chamber and slide a certain part of the rod up to the bullet so it keeps the position. That is how I got my numbers.

My rifle has already been bubba-ized. Not by me, of course. Looks like it has a Boyd's birch monte carlo stock. The end of the barrel where the front sight post is located had been cut off. It now uses a scope. It's a pretty good looking rifle, but I would prefer military configuration.

What I was thinking is perhaps of something along the lines of what Tikka_Shooter was talking about, except just cut a little bit of the threads off if there's still enough for it to screw into the receiver enough. Since there's no front sight, I don't have to worry about the barrel being rotated.
 
Keep in mind that the "number" that you get for an OAL to the lands is bullet specific.

Heavier bullet, lighter bullet- different type (ogive) bullet- it's all going to change, sometimes dramatically. A tangential ogive bullet of the same weight will engage the rifling at a much shorter OAL than a secant ogive VLD.
 
"What I was thinking is perhaps of something along the lines of what Tikka_Shooter was talking about, except just cut a little bit of the threads off if there's still enough for it to screw into the receiver enough."

That's not the way it works. Setting the barrel back involves cutting the face, threads, and shoulder of the barrel enough to shorten the chamber end of the barrel sufficiently to re-cut the chamber/throat area. Just cutting the back end of the barrel off is not the same.

This is "usually" a fairly simple job. Note the word Usually. A couple of months back, I left a fine shooting barreled action at a gunsmith to have the barrel set back 1 thread and re-chamber. Unfortunately, the job was boogered when the lathe operator cut the threads incorrectly and then attempted to "fix" his mistake. Now, he's out the cost of a new Shilen blank and a do-over.
 
Wait, if this is a sporter, why bother with a Criterion barrel, the biggest advantage of those is that they are the same contour as the military barrels, and will fit with the original stock/handguard/bands.

A competent smith can screw any barrel you want into it.

Was the receiver modified when the scope was mounted? Often the rear sight dovetail is ground down. If not, you could try and turn it into a A903A4 clone, with the Criterion military profile barrel and a reproduction stock and scope/mount.
 
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