I noticed that the RCBS form trim die is a great deal less expensive and more avalible than factory 7mm mauser cases.

My question is, when formed from 06 brass will the newly formed cases require neck turning?

quote:

My question is, when formed from 06 brass will the newly formed cases require neck turning?

I've not done this but I'd bet they would....and It's not fun IMO

Unless you have a butt load of free NEW 06 brass I sure wouldn't fool with it. How much would you need in a lifetime 100? Difference in cost is a few$$/100. A 7x57 neck would be formed through the shoulder area of an 06 case.
My guess is yes turning would be required. New 7x57 brass is available in a number of brands frm Grafs, midway etc.

If I was going to form cases from 06 I wouldn't buy a die. Trim the 06 case off close and run in your 7x57 sizer trim to length and turn the neck.

a tad more info

the 7x57 neck is apparently pretty generous
Fired cases from my Interarms Matk X measure .323 across the outside diameter of the neck and sized/loaded ammo measures only .310

#1). There was a time(s) when brass was scarce and a lot of this was done, Wars for instance. Yes, it is doable.
#2). Once you could find fired '06 lying around free. No more. You got lots of '06. They cost too.
#3). To be super cheap, I would point out that the 7x57 was the parent of the .244 / 6mm Remington and the .257 Roberts and if you can find these once fired you can blow them back out probably as cheap or cheaper. luck.

I do in fact have a veritable pile of 30-06 brass laying about. And yet oddly enough no 30-06 rifles.

In fact I picked up 60 FC 30-06 cases from the range last week

quote:

Fired cases from my Interarms Matk X measure .323 across the outside diameter of the neck and sized/loaded ammo measures only .310

Just took a Lapua 06 case and ran it into my 7x57 sizer. Like I said no forming die needed. The issue is at the neck the newly form case has an OD with a bullet in it of .313 however at the neck shoulder the OD is .323. You get that difference because the neck starts on the 06 neck but ends up in the shoulder are of the 06.
Spend the extra $5 and buy 7x57 cases.

I would NEVER pick up brass at a range go to the trouble to resize and then fire them in my rifle. But to each his own. Different brands, lotts, pressures, number of firings thinning due to excess headspace in the parent rifle. Just not worth it to me. Each of my rifles have about 100 cases (except my varmint) and they pretty much last a lifetime.

I just preformed much the same experiment.

With an case formed from fedral 06 and a bullet seated the OD of the neck is .317 just above the shoulder.

FIRED cases from my rifle measure .323 at that same point.

So in my rifle even with unturned 06 cases I still have .006" worth of bullet release. So while tighter than 7x57 cases I's still not exactly a "tight neck" situation.

I'll prolly go ahead and buy the form trim die and experiment more. If forming cases doesn't pan out the die will still be useful for trimming

quote:

Originally posted by Krochus:
I just preformed much the same experiment.

With an case formed from fedral 06 and a bullet seated the OD of the neck is .317 just above the shoulder.

FIRED cases from my rifle measure .323 at that same point.

So in my rifle even with unturned 06 cases I still have .006" worth of bullet release. So while tighter than 7x57 cases I's still not exactly a "tight neck" situation.

I'll prolly go ahead and buy the form trim die and experiment more. If forming cases doesn't pan out the die will still be useful for trimming

How much difference did you get from the neck to shoulder dia? I have no clue if that large a difference in diameters along the neck will have an accuracy issue. Buying the die is up to you. I've used them in the past still needed triming after forming. So I just switched to cutting the brass off a touch long with a dremel cutter formed it then did the final trim.

right at the case mouth I get a measurement of .314

but by less than .070" down the neck the measurement is a full .316 going to .317 down by the shoulder.

Oddly enough the factory rp 7x57 cases with bullets have almost the same variation.

I went ahead and ordered the redding from trim die for $21

If you have no problem with used cases I have 68 used 7x57 RP cases. They are resized and deprimed they came from my boss. We rechambered his 7x57 and I elected to start with new brass for my wife's. I had tossed them in the trash. Say $7 for shipping and they are yours.

quote:

Originally posted by ramrod340:
If you have no problem with used cases I have 68 used 7x57 RP cases. They are resized and deprimed they came from my boss. We rechambered his 7x57 and I elected to start with new brass for my wife's. I had tossed them in the trash. Say $7 for shipping and they are yours.

I've got to leave for work, I;ll shoot you a PM later

a while ago i tryed to make 250 sav. shells out of 06 brass.it took a lot of trial and error to get it right, a lot of diff.dies used to step it down.finally got it right and it was fired till it failed in a model 99 sav, i think about 28 times when i got tired of shooting it still looked brand new.what someone will find tokeep out of trouble.

I have some old Wilson 7x57 vise dies.

They will turn anything into 7x57.