256 Win to 20 cal

[Fazer]

Is there a round all ready done to this. If so what's it called. Thinking about a new project. Thanks

[Calamity Jake]

Don't know of any such conversion but a custom die maker could fix you up.
20 PPC might be a better choice.

[earlmck]

I think we can call that the "20 faster-Fazer".

[Fazer]

I need a rimmed case, I want to use a martini action. Originally I thought of 357 max to 20 cal, but necking down the 256 might be easier. Have to figure out the pressures somehow though.

[BK7saum]

What case length are you looking to have. How about 20 vartarg on a rimmed case. 221 fireball necked to .20 caliber. It would be about 1.400" I think. Or short chamber it and cut dies down to fit.

[rockrat]

Try the 357max first. Run it into a 30 mauser die first then a 256, anneal then try to 20

[Geezer in NH]

Take 1/2 750 liter single malt and it will pass and Light a Cuban cigar with a $100 reserve note and you will come out ahead.

[Fazer]

Thanks for the help. But after reading and actually thinking about what I all ready have close to the planned project. I think I'll just go for 17 Hornet for ease of dies and brass., and I don't have a 17

[rking22]

Gotta make the 256 brass before you can neck it does, dog gone stuff is scarce nowadays! F you know where a bunch is , post it up, several of us shoot it.
I think you'll like the 17 Hornet, there is a 20 version as well, I believe.

[reed1911]

I have about 10K cases on hand, new, runs 80.00 per 100.

[MostlyLeverGuns]

Should be about like a rimmed .20 Fireball based on 17 fireball or 221 Fireball. Could probably use a Fireball reamer, case head dimensions are about the same.

[reed1911]

If he goes with the .357 Max yes. The .256 Win mag is more or less based on the .357 Mag case.

[MostlyLeverGuns]

Yeah, the Fireball case length IS 1.4 and the .256 IS 1.281. In my Marlin 62 .256 I used 221 Fireball cases run through the 256 die and trimmed. Worked fairly well, I have formed 256 from 357 but it is a multi-step, multi-anneal PITA, Powder Valley lists 22 Jet made by PRVI. Maybe a better place to start a 20-256 or even fireform 256. Wasn't the 357 Maxi just a LONG 357 Mag which was a LONG 38 Spcl, to quibble.