Home Forums Reloading Handgun Reloading .357 Sig reloading

Starting out for the first time reloading the 357 Sig cartridge .

Will be sizing first on Rock Chucker w/ a Lee carbide die , then finish off on a Dillon 550 using Dillon carbide die set for the 357 Sig . I have never lubed pistol cases and do not intend to start now .

Will be for the Glock G40 with an Barsto 6” barrel .

Any tips , tricks or things I need to be aware of ?

Recommended loads ?

Thanks Gents .

There were 17 of us who were in the sweepstakes for the Speer Gold-Dots for reloading . No one has any input regarding 357 Sig reloading ?

Guess I'll jump in here I've never had an issue loading them. The one must remember they actually headspace in two places, off the lip and off the shoulder. If your work your shoulders as you would a rifle cartridge and then trimmed lito length , I've never had an issue at all. I think that's where most people have trouble. The bottleneck pistol cartridge is one of the most reliable feeders you could ever have. If you're just trimming to length and not paying attention to your shoulders and your shoulders are out just a hair far they will not go into battery. If your shoulders are set back too much you will have excessive case stretch up on sizing for shorter case life.

I bought new brass from Sig, ran it through a full length sizer die unlubed, no problems, loaded 90gr Lehigh defenders and 125gr barnes copper hp's without issue.

Great , thanks gents .

I procured 500 new , unprimed brass from Starline and checked the shoulder dimension and found them to be .668 “ out of the bag ( SAAMI spec is .677 - .007 @ .4059 diameter ) .

A side note : I know there is a lot debate around how this cartridge headspaces . The SAAMI cartridge drawing specifies( via feature controls ) that the 357 Sig does headspace on the mouth ( .865 “ - .010 ) .

Reloading dies :
Lee 3 die set ( steel )
Lee factory carbide crimp die with the “ Bulge Buster “ kit
Lee factory collet crimp die
Lee 10mm / 40 S & W carbide sizer / decapping die .

My intent is to NOT have to lube these pistol cases . So I will be using the Lee 10 / 40 S&W carbide / decapper to initially size the cases in the single stage press before finishing the cartridges on the Dillon 550 .

Station one will have the Lee STEEL full-length sizer to size the neck and push back the shoulder ( again , with NO lube ) . This cartridge has such a short neck , I’m sure I’ll have no issues not using lube .

Station two will have the Dillon I.D. sizing plug w/ mouth flaring powder through die .

Station 3 will have the standard Lee bullet seating die . However , if I get an unsatisfactory amount of crooked bullet / runout I will probably look into the Hornady bullet seating die as it has the sliding sleeve to keep the bullet centered prior to the seating procedure . The Redding competition bullet seating dies are about the best money can buy ( have several for rifle calibers ) and I will get one for this caliber if the Hornady die does not give me the bullet seating results I’m looking for .

Station 4 will have the Lee collet style factory crimp die .

Powders that I have on hand for loads : AA#7 , AA#9 , Blue Dot and AutoComp .

Bullets I have on hand are Speer 147 grain TMJ .

LOL, damn, sounds like you're setting up for some precision surgery, on another 357 Sig note:

9 grains of Longshot under a 125gr Barnes tac-hp with Fed small pistol primers runs a very soft shooting 1350 fps in the big Sig P226, shot a small grapefruit sized group seated on shop slab off left knee at 25 yards yesterday evening between rain showers, 1.140 col was easy to get and runs perfect in the Sig.