Cheatin Charlie did a dissertation on doing so, somewhere on this forum
if not , contact him, I know he does it, I shoot with him

steveu wrote on Jun 22^nd, 2024 at 4:30pm:


Wonder what he's doing about the big difference in rim diameters with .45-90 being .597" and the Spanish being about .040" larger rim?

Wonder what he's doing about the big difference in rim diameters with .45-90 being .597" and the Spanish being about .040" larger rim? [/quote]

He found some clips to fit on the cases to help extract them, you do have to orient them to catch the extractor.  I have read in the past that some were using 300 WM cases and the clips also.

This is what George is saying.
I tried to form some .45-2.6 into .44-77.
Or was it for the .44-90bn
Kurt

Use magnum rifle casea and turn down the magnum ring on the base to the diameter you need. Then use clips to provide the rim diameter you need. Fire form and trim.  This will work in rolling blocks but not mausers.

I have soldered rims onto 375 H&H cases with good success.   Turn down the case-heads some, solder brass rims on, then turn them to size. Anneal the front half a bit.

CHRIS

Bull,
As you asked, I don't believe there is an easy way with just simple tools to make this brass.  I tried the 45 based cases, wrong head diameter, as mentioned .501 vs .516, that's the biggie, rim diameter being next.  I've fully annealed the case, tried the ring of tape around the solid part of the head and blown out the case with minimal success. I've swaged down the 50-90 case from a .560 head to the desired .516 head, some turning to the case required, both metal flow at the head and rim diameter, not simple hand tools...

The best method I've come up with to date - start with the 348 win.  I have about 300 pieces made for two different rifles I shoot.  These are both in a 44-77 so not exactly the same as what you are seeking, but close.  First step I do is upset the rim - both of my chambers require an .080" thick rim - I would advise against a chamber with this if I had it to do again, my first rifle had this when I got it (this rifle is now gone away but the majority of my brass was made to fit it).  The next step is to anneal the case well and start the forming process in a 43 Spanish die.  There is considerable metal flow towards the head and a lathe is required to turn the head to the .516" diameter.   I've made mandrels for holding the case inside and out.  The final step generally includes neck reaming to thin things up a bit.   
For one of my rifles shooting this case I've reloaded the brass nearly 30 times, (150 pieces) and to date I haven't lost any except to a negligent crunch in the sizing die.  I do a light anneal almost every reload - don't chase color... I've used the cases for both smokeless and black, best performance from smokeless in this bottle neck.
My attached photos show a sample of a case I've been using for  a while (left one).  The one on the right is a case that shows the metal flow - I put the cart in front of the horse on this, didn't get the rim upset first... not impossibe to do now, just messes with the sequence.
A nickel's worth of info...
GT