357/38 rimless query

[Mozz]

I am building a 357/38 rimless, anybody got information on this cartridge.

I essence its a 223 case cut down to 357 length; re sized...

Any information would be helpful.

Regards

[Willbird]

I am building a 357/38 rimless, anybody got information on this cartridge.

I essence its a 223 case cut down to 357 length; re sized...

Any information would be helpful.

Regards

Starline has a 223 basic case that folks use for 357AR. Back ordered right now.

https://www.starlinebrass.com/223-basic

For 357AR they require neck reaming and I would presume the same for your purposes too. I might have a few kicking around from when I had a 357AR barrel, I sold the virgin brass with the barrel but might have some used stuff that you could use trimmed back.

You might also be able to shove some 350 legend cases through a push through sizer and trim them, they only need sized down .01.