Forming .256 Win. Mag from Starline .357 Brass

[donald duck]

Just completed forming 100 rounds of .357 Starline brass in .357 to .256 Win. Mag. First, lubed all .357 cases with Shaler Rislone. 2nd. Ran cases through a .30 Cal Mauser sizing die, adjusted so it only sizes them down a little, length of .256 from bottleneck. 3rd. lubed inside of neck with Shaler Rislone. 4th. ran cases into .256 win. Max sizing die adjusted so case fit mt .256 Win. Mag barrel
Tried each case in Thompson Contender .256 Barrel. All cases fit into action and snapped closed. 5th. Put cases in vibrator to clean case lube. Next step is prime and then load wit cast bullet from Lyman Mold 65 grain.
I am ready to sell the .30 mauser 3 die set including powder dipper and shell holder. they are Lee Green round case Dies. Email dworley790@gmail if interested, price $30.00 plus $8.00 shipping.
Good luck in forming your cases. 100 rounds, no imperfections!!

[DocSavage]

You might want to hold on to that die set just in case you start looseing cases to splits and the like. I know of the 256 win but I don't know case life especially cases formed from 357 mag. Case necks might be too thick causing problem down the road.

[reed1911]

So long as you anneal them they last a long time. If you did not anneal them they may not last more than one firing.

[GRUMPA]

When I make those I use 360DW brass. Using 357mag brass always produced slightly undersized brass for the length. After rimming and cleaning they get annealed which can and will make them last a lot longer..

[Drm50]

I have some experience along these lines with wildcats off 357 cases. I have formed a lot of 22s
out of 357. In fact next to last step is a 256Win sizing die. I have found for the best results the
Brass be annealed prior to forming. To much reduction in one step- without annealing can cause
corragating or shoulder set back. I have no experience with Starline brass. I have found Win brass
best for me- Rem the worst. The only thing I can add to this, don't waste your time with Nickeled
brass, reguardless of brand short case life when reformed. Pic is 22/357s.197789

[MI2600]

I have a Marlin 62, a T/C barrel, and a '92 Winchester rebarreled to .256. Within a few years of the .256 introduction, it was clear the cartridge would probably not last long. Ergo, I opted for the RCBS reforming dies so I could continue to have available brass.