I have a big supply of 30-06 brass that I'd like to re form some of into 7mm brass of which I have none of. I have a excellent newly acquired M-98 (1908) Mauser rifle in 7mm. 7mm brass is fairly pricy here in Alaska.
A quick look see at my Speer manual shows me that except for one dimension (only .001) the 06 brass could be reformed.

Any opinions?

Also....I'm looking for a really nice M-98 chile and Argentine Mauser if anyone has any ideas.

Thanks,

Backspin (Terry) in Alaska

no problem. you'll have to trim to length, maybe anneal, and probably turn the necks. little putter work is all

Hi. I have easily reformed 30-06 to both 8x57 and 8x60 with an RCBS FL sizing die in each calibre by simply pushing the case through, lubed of course, and then trimming to length.

With the decapping/expanding rod removed of course.

Even better would be to use a trim to length die and so you could get the length and use a fine hacksaw to trim off most of the excess 1/8" of case before using your case trimmer machine.

Although less effort might be to offer a swap of 2 x 30-06 for 1 x 7mm?

If the '06 brass has been fired no more than once then it will probably be ductile enough to form without annealing. And if your 7x57 chamber is a bit generous at the neck (which most are) then you won't need to thin the necks.

I've reformed .30-06 all the way down to .22-250. I wouldn't recommend it unless extreme circumstances prevail, but it will work. Reforming to 7x57 is a cinch. Use enough lube, but not enough to cause dents in the shoulders. But if the shoulders do dent they will iron out on the first firing.

Thanks to all of you!

What a great site this is even for a Senior who has reloaded for 50 years!!

I'll buy a RCBS trim die and start from there. I hope the necks are not to thick after trimming but.....I'll deal with that too.

Again much thanks,

Backspin

Glad it help.

I'd call RCBS first just to see if you can use a trim die to reform the cases....or if it is a two step process using the FL sizer die as step one and THEN the trim die.

Although I guess that is handloading anyway you'll have that FL sizing die in any case!

You won't need any special forming or trim dies; just use a sparing amount of lube and sort of milk the 06 brass into your fl die. To avoid dented shoulders. Piece of cake. It is not a two die thing to go from 30 to 7mm, shorter.

Easy to do, you MAY have to thin the neck. If the neck is too thick after forming, it can grip the bullet so tightly when chambered, the pressure will rise to dangerous levels.
You should be able to tell when you seat the bullet, If it fells like you are using a little more pressure than you think would be normal,or if the neck starts to deform or bulge as you seat the bullet,you will need to thin.
I form 25-06 and 7/8mm all the time from '06. I di have to thin the necks on .25-06 and 7mm with my brass.
My two cents.

Wouldn't expect you would have to monkey with the necks. I have formed lots of 270 brass from milsurp -06 brass and never had to turn or ream the necks.

In the area I live there are a lot of 270 Win shooters that do not reload so .270 brass is common and cheap.

.270 is very convenient to form to 7X57.

The fired .270 neck is about perfect for 7X57.
The existing neck requires little sizing. All you have to do is push the shoulder back and trim.

Most case neck reaming or turning is unnecessary.
If you want to check the neck diameter of your 7X57 take a fired case and a tapered punch and wallow the case mouth into a funnel about .020 to .030 oversize. Shove the case into the neck and close the bolt. Extract it.

The funnel will be squashed down to the chamber neck diameter. All you have to do is mike it. If you are skeptical repeat as many times as it takes to convince you that you have the right neck diameter.

quote:

The fired .270 neck is about perfect for 7X57.

A few reloaders/smiths have reamed the 7mm57 to 280 Remington thinking the necks were the same, not so, the 7mm57 chamber neck is larger in diameter meaning the 280 Remington will not clean up 'all' the 7mm57 chamber. When they fire a case in the new? chamber is when they find the neck of the fired cases have two neck diameters.

quote:

I'll buy a RCBS trim die and start from there.

You will not believe how much easier case forming is until you have tried forming with a full length sizing die first. When forming 30/06 to 7mm57 it is necessary to trim 26 inches of brass from the necks, the hack saw makes short work trimming. The neck of the case is finished with a file.

Never discussed when forming long cases to short cases, if the rleoader can keep up with the length of the case from the shoulder to the head of the case and understands the length of the case is used to off set the length of the chamber, the rleoader never has to worry about 'HEAD SPACE!

The new shoulder that is formed is not the old shoulder, the old shoulder became part of the case body, the new shoulder that is formed is new. The new shoulder is formed .221" further back than the ole shoulder. The Old shoulder is erased.

When forming the new shoulder I add to the length of the case from the shoulder to the head of the case to off set the length of the chamber.

Life is much more simpler when there is only one head space.

F. Guffey

quote:

Piece of cake. It is not a two die thing to go from 30 to 7mm, shorter.

I was visiting one of the major die manufacturers, we were discussing case forming, he started with 'all you have to do is etc..". To save time I interrupted him and ask "Have you ever formed a 30/06 to 'mystery case'? He answered with "No".

Trimming the newly formed case would require 39" inches from 100 cases. That is 3 feet 3 inches.

F. Guffey

I don't understand your 3 feet 3 inch thing; I, very simply, full length size in the 7mm die, leaving a very long neck, and the new neck is thence formed from the old 06 body. I place the case in my lathe and remove the offending extra neck length, then trim it to final length in a Lyman case trimmer. A trim die might be useful if you want to do it that way but it is not essential to the process. Most 7mm chamber necks will allow easy chambering without neck reaming or turning. If your new case, with bullet seated, won't easily drop into your chamber then you will need work on the neck diameter. It ain't rocket surgery. I just now, made some 7mms from some LC62 Match brass; had to make sure the shell holder bumped hard against the die or the brass would chamber hard but afterwards, no problems. Seated Hornady 139 grainers; chambered like the real thing. In a PTG reamer cut chamber so it is not a military chamber. Bottom line; go for it. Oh, again, don't use too much lube; no more than regular sizing.
As far as head to shoulder length; that is best determined by your rifle chamber; I like to size for a slight feel when chambering, indicating zero case to chamber axial clearance. Some might call that excessive headspace, but not really.

I'm with DPCD on this. 39" is about 1 metre. That's 100 centimetres.

Now. 30-06 is 7.62x63 and 7mm Mauser is 7x57. So that's at most 5mm or HALF A CENTIMETRE form each case.

Which multiplied by 100 makes...50 centimetres or at most 60 centimetres which is just about 24" in proper measurement units!

The reason for my comment earlier about a FL sizer followed by a Trim Die is that I am not sure if the inside shape of a trim die is shouldered like the actual cartridge case.

Or is in fact just a simple straight "neck diamter" hole with a "square" ninety degree junction between it and the hole that is the diameter of the case body?

If it is properly contoured like a FL die then just use that Trim Die only...although you'll have to, if fired cases, FL size at some time anyway.

Most trim dies have a FL sizer body dimensions but the neck is .010 larger than the FL neck die. RCBS trim dies are set up like that.
I once loaded for the 6.5X53R Dutch using a trim die to form .303 British to fit the chamber. Then I neck sized with a 6.5X55 and seated with a 6.5X55.

quote:

Originally posted by enfieldspares:
I'm with DPCD on this. 39" is about 1 metre. That's 100 centimetres.

Now. 30-06 is 7.62x63 and 7mm Mauser is 7x57. So that's at most 5mm or HALF A CENTIMETRE form each case.

Which multiplied by 100 makes...50 centimetres or at most 60 centimetres which is just about 24" in proper measurement units!

The reason for my comment earlier about a FL sizer followed by a Trim Die is that I am not sure if the inside shape of a trim die is shouldered like the actual cartridge case.

Or is in fact just a simple straight "neck diamter" hole with a "square" ninety degree junction between it and the hole that is the diameter of the case body?

If it is properly contoured like a FL die then just use that Trim Die only...although you'll have to, if fired cases, FL size at some time anyway.

OK. Again thanks to all of you for your opinions!!
I have now finished a 40 round batch of FC 30=06 brass into nice, shiny 7mm cases...in one (not easy) push through my new 7mm size/decap die. MINIMAL lube!
All tumbled clean and look great. I have a power trimmer that shortened that long sized neck very quickly.

Thanks for the .270 brass tip. I do have some of that from years ago and it should form easier than the 06,

I'll buy all of you an adult beverage....sometime?

Backspin
(retired disabled Army Aviator)

Good job and if I am ever in AK, I will take you up on your offer.

quote:

MINIMAL lube!

I would NOT do it like that again! Be sure that being too economical with the lube WILL come back and bite you.

Been there and done it too often to ever see it as anything other than a trap waiting to catch me.

Any chance of a before and after pic of the 30-06 next to the 7mm?

Yes, minimal lube; you do not need any more lube than it takes for regular re-sizing. If you use more, you will definitely get neck dents. It is really not hard to size these. Look at the last one; I used too much lube and you can see what happens; in fact, you should milk the case up into the die and wipe the lube around; don't horse it into the die all at once. Here are some I did yesterday from LC 62 military brass.