Can I make 6mm brass out of...

[Classicvette63]

.257 Roberts or 7mm Mauser cases? I know the 6 and the .257 are based on the mauser, but how hard is it to do? See, I have a bunch of Roberts cases and a few Mauser cases but I don't have a gun for either. Can I just run them thru my 6mm die? or should I just buy a .257 and 7mm?

[Hammerforged]

Yep, the 6mm Rem. is based on the Mauser case. Just lube the neck inside and out and run it through your sizing die.

[Jack]

Yes, you can make cases from either. The 257 cases would probably be a bit easier.
Just lube normally, and size normally, using the 6MM sizer. I suspect you won't be able to tell by feel whether it's a 6mm case or a 257 case being sized.
Be a slight bit more effort with 7x57 cases, but nothing to worry about.

[Catfish]

When necking down 1 case to form another you do increase the neck thickness of the brass. The more you take them down the thicker the necks become. I have never found this to be a problem with any factory chambers but often have had to turn necks for custom chambered rifles. The thick necks also reduces the case capisity slightly and increase the presure nessary to pull the bullet. In other words you may have to reduce the amount of powder you are now useing to keep presure where they are now. I formed some .204 brass from .222 mag. brass befor the .204 brass was avaliable. I really haven`t compaired the accuracy side by side yet, but the fromed brass gives me close to the neck expantion I like in my custom chambers, abt .002. It will also take alot more presure to pull the bullets from the from brass which I personally don`t think matters much as long as the bullet pull is conisitant.

[Rocky Raab]

All correct. And I'll add my usual little trick: run the lubed cases through your seater die first. Because it's a bit larger diameter in the neck (to allow a seated bullet to enter it) it'll serve as an intermediate die.

[skeet]

Just taught me somethin else new. Never thought about that seater die thingie...Thanks I have to make so jet brass. I do have lots of 357 new though.

[Classicvette63]

Worked slick as could be. Now, if I could just make some out of .30-06 brass, I'd be set. I must have 5000 '06 cases.

[Jack]

You can, but it's far more work, and just not worth it when brass is readily available for the cartridge in question.

[Talon]

Remember

Imperial Die Wax

Peace
Talon

[Catfish]

Rocky`s seater trick will often save buying a form dies set, but from .257 to .243 it should not be nessary. I`ve been running 6 mm cases straight to .224 without the extra step. When forming .17 AH brass from Hornet brass the seater die trick will save alot of brass. Those thin neck on the Hornet brass will fold if you try to take the tp far, but I usually use the seater when forming .17-223 brass also. It porbibly wouldn`t be nessary with new brass, but I use alot of mil. brass.

[PJgunner]

Originally posted by Classicvette63
Worked slick as could be. Now, if I could just make some out of .30-06 brass, I'd be set. I must have 5000 '06 cases.

Sounds like a darn good excuse to buy a rifle in 30-06 to me.
Paul B.