Inquiring about cast loads for the 357 Sig

[LRRifleman]

Greetings!

I am contemplating a purchase, and I am finding the 357 Sig round to be very tempting. The problem is, 98% of my handgun shooting entails the use of cast bullets. Upfront, I don't have the latest version of Lyman's Cast Bullet Handbook, but hoping my kids will have it under the tree!

Has anyone here developed, and uses, a cast bullet load for the 357 Sig? I am equipped to PC bullets, so that won't be an issue for me.

Thanks in advance for your help!

[MT Gianni]

One of the advantages of smooth side cartridges is the necks ability to hold bullets straight and aligned with the chamber. I know of no cartridge with a shorter neck than the 357 Sig. I like shooting cast in the 40 S&W parent case but have never met anyone shooting cast in the sig.

[dkf]

Cast data for .357sig is next to nil. Maybe the lyman cast book has data, don't have it myself. I just base my start loads off of jacketed data. The bullets I use most are the 9mm Ranch Dog bullet from NOE (GC and PB) and a 35-147S (PB) from accurate. But I also have some 125gr molds I use every now and then. I usually size to .358".

[dkf]

Forgot to mention. Bullet/Mold selection is important for .357sig. The nose cannot be too long forward of top band and the lube groove (if the bullet has one) can't be too far forward. You want to avoid bullets with crimp grooves if you can. A lot of 9mm bullets won't work with the SAAMI 1.140" COAL of .357sig. You basically need a solid band (or as solid as possible) for the neck of the small neck of the brass to grip. This helps keep adequate neck tension and prevent bullet setback. Though with the right powder choice setback can be taken out of the equation using a compressed charged.

[McFred]

The Lee 358125 6-gang mould works for me in 357 Sig. I use accurate number 7 powder.

Western Powders has published load data for 115gr, 124gr and 147gr lead projectiles for Accurate powders AA#2, AA#5, AA#7 and AA#9.

[dansedgli]

I've been shooting 168z's in mine from Accurate molds.

Slow powder and 1080ish fps for IPSC.

[osteodoc08]

There’s data and boolits that will work, but I can think of several better cartridges. I’d advise to keep looking if you’re open to advise.

[fcvan]

I had picked up so much 357 SIG brass that I had to buy a drop in barrel for my Glock 22C. I had a buddy who used to carry a 357 SIG and found out I was scrounging. He gave me his empties and 600 rounds of factory. I already had the Lee 358-125 RF so I cast and PCd some up.

7 grains of Unique gave me 1325 FPS as opposed to the factory 125 FMJ load at 1350 FPS. I don't shoot it much, there is definitely a similar recoil pulse as the 40 S&W, but with less muzzle rise. I do like the lack of a compensated barrel but I also have a drop in barrel for 9MM which uses only 5 grains of powder. That and I sometimes load the 9mm with the Lee 356-102 RN (mine drops at .357) and saving lead when just shooting tin cans makes sense.

Neat little cartridge, the 357 SIG, I am certainly not unhappy with paying 100 bucks for the drop in barrel and 25 bucks for the dies. I already had the mold which is the same profile as the factory rounds I have. I have a neighbor/former co-worker who had a Glock chambered for the 357 SIG. His chief complaint was the cost of the rounds which at the time 50 bucks a box. I gave him 100 rounds of factory and 300 rounds of reloads. I also showed him how to load those rounds and told him to call whenever he needs to top them off again. He wants to start reloading but he is currently restoring an old Jeepster, that and still raising kids :) I'm retired!

[McFred]

I had a buddy, he gave me his empties and 600 rounds of factory.
I need some friends like that. :)

What alloy did you use for your 358-125 RF? That's some good pressure to get them to 1325fps from a 4" barrel.