Decapped (like all my pistol caliber brass) in a dedicated decapping die (I use RCBS for pistol & the LEE for rifle calibers). Run through the Thumlers, then a 40 S&W sizing die. THEN through the 357 SIG sizing die, which happens to be part of the Hornady Custom set. Fine-setting this die the 1st time I reloaded 357 SIG took a while, but this step effectively sets the shoulder for all the rest.

Then trip #1 through the Wilson case gauge.

Expansion and bullet seating via Hornady, finished with LEE 's FCD (which is collet-style). Then trip #2 through the Wilsons for the (finally?) finished product.

May be a little OCD, but it works for me: 357 SIG is one of my favorites to reload and shoot. Wish someone just made an affordable carbine...?

Cheers!

P.S. All (99.9%) my 357 SIG brass was either new Starline or once-fired Speer that I reprocessed. I have yet to need to trim a case and have thrown out less than a helf-dozen orphans that somehow managed to show up one day...?