.30-03 Ammo

[pcaru1]

Is there any way to reproduce a .30-03 cartridge from a .30-06? I have a RIA 12-05 barreled receiver that has a TE reading of 7. I used a Forster No Go and Field gauge set to check headspace and it passed. MW is 3.5 with has a dark bore and strong lands and grooves. The barreled receiver seems to be a Sedgley rebuild. Can I make one of these rounds as a dummy to check if the barrel is still in this caliber? If so how? I have read that this case was the forerunner of the current .30-06, which is just trimmed .07 shorter with a 150gr Spitzer bullet instead of a 220gr round nose. What dies would I be able to use?
I looked to see if there are any for sale and the ones I found were REAL expensive. Any info is appreciated.

Information

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[Patrick Chadwick]

Is there any way to reproduce a .30-03 cartridge from a .30-06?

Why bother with a .30-06 case? The result would be seriously under length. But there is a simple solution:

It appears that the .270 WIN was originally devised by sizing down the neck of a .30-03 case.
So if you want to make .30.03 cartridges, simply get hold of some new .270 WIN cases and expand the neck!
If I had to do it I would take .270 WIN cases, anneal the necks, open them up with a .300 neck expander and then full-size in an ordinary .30-06 die that is set out the necessary 0.07".

For later resizing, find a washer of appropriate thickness (or turn one on a lathe) that supplies the extra length, so that you don't have to keep resetting the die if you use the .30-06 for making up .30-06 ammo. But .30-06 dies are cheap enough that I would buy an extra set for 30-03 use and label it !

Or simply fire-form, if you are experienced with that technique.

[Patrick Chadwick]

Can I make one of these rounds as a dummy to check if the barrel is still in this caliber?

Not necessary. Take out the bolt. Push a .30-06 case in by hand as far as it will go. Hold it in place. Take a 1/4 brass or wooden rod and push it GENTLY into the barrel until it is just touching the bottom of the cartridge case (internally). Make a fine mark on the rod where it enters the barrel. Replace the bolt and close it.* Now push lightly on the 1/4" rod again. If the chamber is still in 30-03 it will move down by the 0.07" difference and the mark will disapppear into the muzzle. If it does not move more than a few thousandths, the chamber has been recut and, whatever it is now, is no longer .30-03.

*Depending on what the actual chambering is, the extractor may or may not slip over the rim. If in doubt, pull back the bolt and finagle the case in from the magazine so that the extractor is engaged. Simply feeding the empty case from the magazine will probably not work because, without a bullet, the case mouth will snag on the feed ramp and chamber entrance.

[Parashooter]

Patrick, it appears from the posts above that you believe the .30-03 case has a longer head-shoulder dimension than the .30-06. However, the only significant dimensional difference between the two cases is the length of the neck. Headspace dimension is the same for '03 and '06. Consequently, there's no need to back off the sizer die (or to refrain from using .30-06 ammunition in a .30-03 rifle). Also, the exercise you describe with the marked rod will not provide any useful information for differentiating between '03 and '06 chambers.

FWIW, the .270 Winchester chamber shares its headspace dimension (SAAMI max 2.0587" to .375" datum) with the .30-03 and .30-06 but does, indeed, have the extra neck length of the '03.

There are several practical ways of measuring chamber length, the simplest being the insertion of a greased 00 buckshot atop an empty case into the chamber and closing the bolt. The chamber mouth will leave a distinct impression on the buckshot that can be measured to give total chamber length from the bolt face. Examples below are in 7.5 Swiss, but the method works the same with US .30 caliber rifle chambers.

[AKA Hugh Uno]

for Pete's sake, just stick an M2 ball round in the rifle and SHOOT IT. The 30.06 can be chambered and shoots FINE in a 30.03 chamber (if it even IS an .03 chamber). Don't believe me? Look (real) CLOSE at the picture (below). If it is an .06 chamber, it will also (obviously) be fine.

[Bruce McAskill]

If it's been rebuilt by Sedgley the odds are it's now a 30-06 barrel on it.

[Patrick Chadwick]

Patrick, it appears from the posts above that you believe the .30-03 case has a longer head-shoulder dimension than the .30-06. However, the only significant dimensional difference between the two cases is the length of the neck. Headspace dimension is the same for '03 and '06. Consequently, there's no need to back off the sizer die (or to refrain from using .30-06 ammunition in a .30-03 rifle). Also, the exercise you describe with the marked rod will not provide any useful information for differentiating between '03 and '06 chambers.

Thanks for the clarification!

FWIW, the .270 Winchester chamber shares its headspace dimension (SAAMI max 2.0587" to .375" datum) with the .30-03 and .30-06 but does, indeed, have the extra neck length of the '03.

Well, at least I got that right!