7mm Mauser from '06 or 308

[Lead melter]

I have a line on a '93 Spanish Mauser for next to nothing, and expect it to be 7mm Mauser but have not slugged the bore since it is not my rifle yet. If I pick it up, is it better to use '06 brass or 308 brass to anneal and the form using the resizing die? Both have specs that seem close enough to convert, but the '06 brass has a bit longish case body, in my opinion.

Any tricks of the trade with either brass? Opinions are also welcome.

[richbug]

308 is too short.

30-06 works fine, in a commercial rifle the necks might end up too thick, but in an old Mauser they should be fine.

Imperial sizing die wax would be my choice of lubes for the task.

[madsenshooter]

You can get a little headstart on the neck by sizing the 06 brass first in a 06 die with the expander ball removed. Hope you have a heavy duty press, it's going to take quite a bit of force to change all that shoulder into neck.

[1Shirt]

Unless money is real tight, and you have on hand a neck reamer because of thickness of neck as you size down, recommend seeing if you can find some once fired 7MM Brass on line. If you do use O6, and ream, suggest you anneal befor you trim. Good luck.
1Shirt!:coffee:

[Hickory]

I have done this before, 30-06 to 7x57.
All the above advice is good and should be heeded.
you need to do two other things.
1) dissasemble sizing die and clean it removing all oil and grease.
2) when reforming the brass from 30-06 to 7x57 make sure that the neck and shoulder area is clean and dry, void of all oil and grease. So that no wrinkles form in this area.
Good luck and have fun?

[jonk]

I've done this a good bit. Never had to neck ream but you may well have to, depends on your chamber.

I use an electric cut off saw from harbor freight, rough trim to length with that, size in regular 7mm dies, then final trim. A size and trim die would also work great if you want to go that route.

It's not that it's hard. Or even that involved. It's just a question of what is your time worth to you... for me it's worth less than a bag of new 7mm brass at $40+ per bag since I have a ton of 06 brass on hand.

[dualsport]

I've formed a lot of 7x57 from '06 using the RCBS form and trim die. You just run it up in there and cut off what sticks out. Simple Then I chamfer the neck to clean it up. Never had any problems using them in several different Mausers, a Ruger 77, and a Rem. RB.

[atr]

all the above advice is "spot on"...I have used 30-06 brass and a VERY strong press for resizing to 7x57....BUT...there is alot of good 7x57 brass on the market so if it were me I would got that route

[StarMetal]

I don't find sizing 30-06 to 7x57 taking that much press force unless you try to do it in one stroke. Best way for someone new at it is to screw the die out pretty far where it only sizes down part of the case. It's also a good idea to unscrew the decapping pin. You can expand and decap them after you have them finished. So you have your die screwed out size them all, then turn the die in some more and size them again. Then repeat repeat until you sized them with the die screwed down all the way. I like this method and so does Maven because I see him post it much. Good idea to clean the brass first too. If you have to make the neck less thick I feel the best way is with an outside neck turner. One final thing, somehow keep the ammo very well identified so it's not mistakenly fired in a 30-06 because that's what the head stamp says it is.

Joe

[Gerry N.]

Forming 7X57mm from .30-06 is dead easy. I do it on my little Lee pot metal reloading press with a lee full length size die. Remove the decap/expander stem, size your cases. The neck will be very over length. I used a little tubing cutter, the "Imp" to rough the case necks, then trimmed to length on a Forster case trimmer, followed by an inside/outside neck chamfer. Then reinstall the decap/expander stem in the size die and make one more pass. It takes less time to do it than tell it. My 7X57mm brass is formed from GI brass I was given in the early 1960's. One other step with GI brass is to remove the primer crimp.

Never had to anneal any of it. If you're using commercial brass, this step is, of course, not necessary. I've had the best results with Imperial Die Wax lubing every case. Lee's case lube works well, too. Remember to lube inside the necks when expanding them.

Your mileage, as always, may vary.

Gerry N.

[MT Gianni]

If you have to buy brass to reform I would buy 257 Roberts and neck up. If you have the '06 and it is military, be sure to work up your loads. 7x57 brass is tough to find on it's own.

[GrizzLeeBear]

If you got a bunch of 06 brass, go for it, but get one of these, $24 well spent:

http://www.midwayusa.com/viewProduct/?productNumber=524910

I don't have a 7x57 but I've formed lots of 8x57 with the redding die. The Redding die is a lot cheaper than the RCBS and I also like that the Redding die is "chamber" size, not sizing die size. Using the Redding die, I get lots less wrinkes in the shoulders because it doesn't do all the forming in one shot. After running the 06 brass into the trim die and cutting off what sticks out with a hack saw, I clean up the rough cut with a chamfer/debur tool. Then FL size them in the regular sizing die. Then trim them to trim lenth in a regular trimmer. Don't have any problems with necks with the 8x57, but since your sizing the neck down further on the 7mm it will depend on your rifle if you have to ream the necks or not.
For lube use Imperial Sizing Die Wax, it is THE lube when reforming brass. Don't need too much. Just wipe two fingers in the wax and roll the case between your thumb and the two fingers just below the shoulder. Do not put any lube on the shoulder, it will cause wrinkles in the new shoulder. If your case are coming out with wrinkles your using to much lube. It will take some effort on the press, but if it feels like it wants to stick - STOP. Back the case back out and apply a touch more lube and try again. If you try to force it, you risk a stuck case in the die. I usually have to to this 8 or 10 times in a batch of 50. I find it better to err on the side of slightly to little lube to prevent wrinkles and having to relube one every now and then.
Theres a bit of "feel" to forming cases. After doing a bunch you will start to figure out how much lube, when a case feels like it wants to stick, etc.

[Bob S]

I don't find sizing 30-06 to 7x57 taking that much press force unless you try to do it in one stroke. Best way for someone new at it is to screw the die out pretty far where it only sizes down part of the case. ... So you have your die screwed out size them all, then turn the die in some more and size them again. Then repeat repeat until you sized them with the die screwed down all the way ...
Joe


+1

I didn't like the idea of having 8mm brass and ammunition with Frankford Arsenal or Lake City headstamps, so I quit making 8mm from 30-06.

There is so much good commercial 7mm and 8mm brass floating around these days that I find it counterproductive to reform anything.

Resp'y,
Bob S.

[StarMetal]

+1

I didn't like the idea of having 8mm brass and ammunition with Frankford Arsenal or Lake City headstamps, so I quit making 8mm from 30-06.

There is so much good commercial 7mm and 8mm brass floating around these days that I find it counterproductive to reform anything.

Resp'y,
Bob S.

Bob,

When I use 06 brass in my rifles I use it mainly for the thicker necks trying to enhance my accuracy, not because I can't find commercial brass for it. It's probaby the best brass to get the Swede to shoot cast accurately.

Joe

[Bob S]

Bob,

It's probaby the best brass to get the Swede to shoot cast accurately.

Joe

Well, I have CG63/80 inbound. Maybe I'll have to try that.

A 6.5 x 55 mistakenly chambered and fired in a Springfield probably won't cause any harm other than acute embarassment; an 8x57 mistakenly chambered and fired in a Springfield can ruin your whole day. (It takes mightly effort to get the bolt to close on an 8x57 cartridge in a 30-06 chamber. You would think that it would make the shooter stop and investigate the "issue", yet several folks have managed to ruin Springfields and injured themselves by doing just that. Darwin Award. After reading Hatcher's Notebook ~45 years ago, I tried it, with a dummy cartridge. It can be done, but you have to perform some unnatural acts on the bolt handle ...)

Resp'y,
Bob S.

[StarMetal]

Well, I have CG63/80 inbound. Maybe I'll have to try that.

A 6.5 x 55 mistakenly chambered and fired in a Springfield probably won't cause any harm other than acute embarassment; an 8x57 mistakenly chambered and fired in a Springfield can ruin your whole day. (It takes mightly effort to get the bolt to close on an 8x57 cartridge in a 30-06 chamber. You would think that it would make the shooter stop and investigate the "issue", yet several folks have managed to ruin Springfields and injured themselves by doing just that. Darwin Award. After reading Hatcher's Notebook ~45 years ago, I tried it, with a dummy cartridge. It can be done, but you have to perform some unnatural acts on the bolt handle ...)

Resp'y,
Bob S.

Bob,

One of my friends sons, years ago, shot a 35 Rem out of a 8x57 98 Mauser. He got a buck too!!! Said the rifle really kicked. I asked what ammo he was using and he pulls out these 35 Rems. :groner: I forget the bullet weight but they head spaced ok in that longer chamber. Imagine how that bullet looked when it exited the muzzle, like the Cruise Missile.

Joe

[Mk42gunner]

Well, I have CG63/80 inbound. Maybe I'll have to try that.

A 6.5 x 55 mistakenly chambered and fired in a Springfield probably won't cause any harm other than acute embarassment; an 8x57 mistakenly chambered and fired in a Springfield can ruin your whole day. (It takes mightly effort to get the bolt to close on an 8x57 cartridge in a 30-06 chamber. You would think that it would make the shooter stop and investigate the "issue", yet several folks have managed to ruin Springfields and injured themselves by doing just that. Darwin Award. After reading Hatcher's Notebook ~45 years ago, I tried it, with a dummy cartridge. It can be done, but you have to perform some unnatural acts on the bolt handle ...)

Resp'y,
Bob S.

This is why I form my 6.5-06 brass by necking down .30-06, instead of expanding .25-06.

Many years ago my best friend's Dad tried to load a .25-06 cartridge in his son's .22-250; Luckily it wasn't the other way around. Both rifles were Browning B-78's.

Be safe out there,

Robert

[dualsport]

I'm going a ways off topic regarding the original question, but speaking of cool reforming dies, I got a set long ago from RCBS that makes shot shells for the .45 acp from '06 or similar brass. They feed thru the magazine and are a real hoot to shoot. Sorry.

[StarMetal]

I'm going a ways off topic regarding the original question, but speaking of cool reforming dies, I got a set long ago from RCBS that makes shot shells for the .45 acp from '06 or similar brass. They feed thru the magazine and are a real hoot to shoot. Sorry.


I have a set of 7 dies for forming and loading the 45 acp into the 38-45. In about the middle of the four forming dies is produced the perfect case for 45 acp shotshells. That's what I use. I also use 45 Win Mags for both the 38-45 and the shotshells. The rifle shells are too thick and not the right primer pocket for a larger pistol primer.

Joe

[RayinNH]

I've used .270 Winchester brass to reform to 7x57. I don't have a .270 so brass mix up was also eliminated...Ray

[MtGun44]

Get real 7x57 brass, it is readily available from Remington and often from Win.

Graf has PRVI, Rem and Win, 40 cents for PRVI, 54 cents for Rem or Win. PRVI
is good quality brass, and of course so are Rem and Win.

http://www.grafs.com/metallic/736

Bill

[clearwater]

I have a line on a '93 Spanish Mauser for next to nothing, and expect it to be 7mm Mauser but have not slugged the bore since it is not my rifle yet. If I pick it up, is it better to use '06 brass or 308 brass to anneal and the form using the resizing die? Both have specs that seem close enough to convert, but the '06 brass has a bit longish case body, in my opinion.

Any tricks of the trade with either brass? Opinions are also welcome.
I'd say do it for the fun!

I make 7x57AI brass out of 06.

I run it through the ai sizer without the expander first, using graphite inside
and outside the neck and imperial wax on the body.

Then use a cheap tubing cutter (I got at Harber freight for a few dollars) to
get it near to trim size.

then full size again (this time with the expander stem in) trim and chamfer.

For my ackley improved it does need to be fireformed, to reach full capacity.

I like to anneal after the fireforming and weight sort the brass.

I use LC mil brass as it doesn't have any caliber markings.