What caliber(s) of brass is(are) best for converting to 7mm Mauser?

Hi everyone, just bought a Brazilian 7mm. Have a Lee mold, but no brass. I have 30-06, .243, .270, and 8x57 brass. 8mmFan

257 Roberts is almost a perfect match.

Thanks Bullet Maker. That's another caliber I've always meant to use but never have. Don't have any of that brass either, of course.

Forgot to mention that I also have some 308 brass laying around. 8mmFan

http://www.grafs.com/catalog/product...12656/inline/1

Grafs has PPU ready to ship. I have used it and it is better than US brands.

the 8x57 will work. Just check and see if the neck is to tight after seating bullet for your chamber. Sometimes sizing down also means neck turning or inside reaming.

Thanks Guys. I will just order the Graf's. Easier than converting, I think. Very much appreciated!

I use 270/30-06 to form my 7x57

In the conversion table, all 7x57 Mauser's are the 30-06 as the parent case

Not many people in my area reload .270 so the cases are plentiful and cheap or free.

A fired .270 neck is almost exactly perfect for a 7mm Bullet. Push the shoulder back, trim and anneal then FL size.

Skip this if you own a .270 since the 7X57 may chamber in the .270. Wrong headstamp is the problem.

I think buying the right brass is the best way to go, at least if you still use the others you have. If so, you aren't saving in the long term by using them. But if you really want to form something, the .270 is the one to choose. Reducing the neck on .30-06 is easy, and setting back the shoulder is easy, but I would prefer not to do both at once.

6mm Remington brass might work as well.

Kinda depends on what you have and what else you reload and shoot. I have no .270s, but do have a couple of .30/06s, so I use .270 brass to form 7x57. Helps reduce headstamp confusion. .270 and .30/06 will need to be annealed before re-forming. You can use a tubing cutter to remove the bulk of excess length.
8x57 is easier to convert as it will not need as much trimming. .243 probably will not blow out enough to reach a length of 57mm.

I use a size and trim die to convert 30-06 to 7x57. After you size the 30-06 case, it helps to cut the excess neck with a hacksaw, and then trim with a file. As brass in the neck area tends to be thicker than a stock 7x57 case, I do neck turning as a final step.

I also anneal all converted cases with a Vertex machine

I use .270 brass for the headstamp reason, I don't have a .270 to load for.

As an aside that Lee mold will more than likely be too small unless you got a Lee screw-up on the plus side. You'll likely need a boolit about .288 diameter for that Brazilian.

your .243 and .308 cases are too short.

8x57 is just a pass through the forming die

the 30-06 and 270 cases need to be trimmed back 6mm and then reformed. Most commercial brass should reform without a need for neck turning if you have a military chamber. If you had a commercial chamber, I'd heartily recommend the neck turning of the reformed brass.

Bruce

if someone hasn't mentioned this already, buying the little hobby chopsaw/tubing cutter thing harbor freight sells ($35) will make life a LOT easier. I bought it for forming 577/450 Martini Henry and 577 Snider brass and use it all the time now.

When I reform brass to if I think there could be some confusion in what it is I use an electric engraver to obliterate the cartridge stamping.

Quote:

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Originally Posted by rr2241tx

http://www.grafs.com/catalog/product...12656/inline/1

Grafs has PPU ready to ship. I have used it and it is better than US brands.

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This. For the price of the HF takes-up-space-and-struggles-to-cut-brass you are halfway to a bag of the real stuff.

When I bought my mauser in 2009, I bought 500 rounds of PPU from gunbroker. I am still reloading those cases to this day. Probably less than 5 failed cases so far.

Hi 8mmFan
I know I am a little late in replying. Use the 30-06 brass that you have and lube a little and run through your
FL sizing die and then trim for length. I looked at the SAAMI specs and other references and this should work fine. You
might want to anneal the neck/shoulder area because this is rifle brass and you are working the neck and shoulder area
a wee bit. You should look at the inside of the neck because there might be some ridges in there if you are using
military brass, I ran into that when I was reforming some brass, commercial should be fine. Use some way to ID
this newly made brass so you don't get confused with identity when using commercial. Just my thoughts