Work Hardening brass

[JeepHammer]

In the process described above,
Where are you going to find suitable 'Cartridge Brass' alloy bar stock to start with?
When I hand machined oddball Sharps cases I ran into the issue of alloy mixing, with common 'Brass' rod being way too hard to start with, and without the zinc alloy being correct the cases split.

If you want to harden the head, you will have to machine the case blank, bore the bar stock, build a socket die to insert head into, and build an impact ram to fit I to the case.
Using something like an air hammer you would be able to work harden the head area without hardening case walls.
Then you would have to cut rim & primer pocket, this will require a mandrel inside the case to keep it from deforming as you clamp the case by the walls to cut the rim/primer pocket.

Then you could get around to annealing the top of the case for neck/shoulder forming...

Back before long stroke hydraulic presses were invented, manufacturers tried both casting case blanks and machining, and cutting billet into blanks (what you are talking about).
Copper can be spun (rimfire) but brass has to be extruded/drawn and/or machined.

Good luck.

 

[Unclenick]

It's also cold-rolled to harden it. It's much more common to see 360 (aka 36000) brass (close to Muntz metal) in rod form and the full hard temper not quite as hard as you like, though it's only about 10% low. 260 (aka 26000 brass or cartridge brass) is also available in rod through aircraft metals suppliers, but you usually have to call and ask about it. The problem is that 260 is valued for it malleability, so it's usually soft unless rolled into sheets, so hard extruded rod can take some looking to find.

Std7Mag, what peak pressures are you looking to contain here?

 

[std7mag]

Would like to possibly be able to get to 58,000 psi. Hence like a 257 Roberts +P.

With the amount the rim is rebated i don't realistically see 62-65K in it's future.

I'd kinda like to know what Lapua did to the 416 Rigby case to make it viable for the 338 Lapua.

I had seen/heard of people machining down the 404 Jeffery case to get 425 WR, but i'm looking for somewhat higher pressure than 425 WR. Hence the removing of metal from a case that already has a set inside diameter and depth (profile?) seems counter productive to me.

 

[Unclenick]

You don't want heads that are extra soft for that. You could go with a thicker head, as another possibility, but most people don't like to give up powder space. If you didn't want to reload, you could go with turned mild steel cases. Normal pressure signs won't work with them, though, so you'd want to own a Pressure Trace or other pressure testing instrumentation.

Assuming you are using a standard head size, have you tried looking for basic brass that can be formed?

I'd kinda like to know what Lapua did to the 416 Rigby case to make it viable for the 338 Lapua.

The heads are different enough that I don't see how it could be done. The Rigby rim would have to be thinned and the extractor groove set back and narrowed and the extractor groove relief angle somehow pressed back and recut to a steeper angle. The Rigby's are also a couple of thousandths wider at maximum, but as most cases are average rather than maximum, that element could be ignored most of the time. The CIP drawing for the 338 LM and for the 416 Rigby show the differences pretty clearly.

 

[HiBC]

I don't know if this helps you,but the Nosler magnums (or some of them) usea .404 Jeffery parent case

https://www.americanrifleman.org/articles/2017/5/3/upping-the-ante-the-30-nosler/

 

[std7mag]

I had read several sources that claim the 338 LM case used the 416 Rigby as the parent casing.
Several had tried with the Rigby casing to get it to work, but kept running into pressure issues. Lapua finally managed it.

To get the speed up, Lazzeroni is known to be a high pressure cartridge line. Also reportedly Lazzeroni's have a "very hard head".