.357 sig reloading using .40 cal brass

[DVC1911]

Have been shooting both 357sig and 9x40 for years. No problems at all using 40SW cases. Very cost effective. I prefer the 9x40 because it stacks better in the Magazines.

I have been shooting two loads over the last year:

15.2grs H110 OAL 1.260 with 124 Aim Bullet. PF is 174. Makes the comp work really well.

8.5 gr Longshot 1.260 with 124 Aim Bullet. PF is 172. Very soft to shoot, some muzzle flip because there is not enough gas to work the comp. This is a very clean load to shoot.

DVC

 

[Mike Oxlong]

So you are using short brass in your gun and we are wrong? What you are using is called 9x40. If it's working in your .357 sig gun then good for you. It isn't proper and likely won't work very well for most.

9x40 and necked down .40 S&W brass in a .357 SiG die are NOT the same thing. 9x40 is a wildcat cartridge that has a much different shoulder angle than .357 SiG. I'll try to dig up some brass and post a photo.

 

[B]

9x40 and necked down .40 S&W brass in a .357 SiG die are NOT the same thing. 9x40 is a wildcat cartridge that has a much different shoulder angle than .357 SiG. I'll try to dig up some brass and post a photo.

Regardless, he says he uses both with no issues. I am just saying that it isn't ideal. I know what the 9x40 is. You and I have done this before...

 

[mike v]

Reply to Quigley. I use my .40 cal. mags.

 

[sandman]

I've loked at some loading data and I may try HS-6 with 124 g Aim or equal bullets. I have aquired some .357 brass....and factory ammo $$$$. Once I receive my dies from Dillon I was going to perfect a load to use in .357 brass....then go to the .40 brass.

As DVC 1911 has stated, I have met shooters who use the .40 brass at IPSC comps...but I don't use a compensator or an open gun, I just shoot production...the H110 is a hot load...no?

Guys, any info I can get with regards to reloading data etc...is greatly appreciated. Thanks

 

[Canuck223]

So you are using short brass in your gun and we are wrong? What you are using is called 9x40. If it's working in your .357 sig gun then good for you. It isn't proper and likely won't work very well for most.

9x40 and necked down .40 S&W brass in a .357 SiG die are NOT the same thing. 9x40 is a wildcat cartridge that has a much different shoulder angle than .357 SiG. I'll try to dig up some brass and post a photo.

Regardless, he says he uses both with no issues. I am just saying that it isn't ideal. I know what the 9x40 is. You and I have done this before...

The thing to remember is that there is a huge difference in loading for a straight walled case and a bottle necked case.

While the chamber may be cut to headspace off the mouth, it will likely headspace just as well off the shoulder.

If it was me, I'd be spending the time to size, fireform, and resize a few cases until I found the correct sizing depth that allowed proper headspacing and no problems chambering.

My only concern about using .40S&W to form .357Sig ammo is case mouth tension and crimping consistancy.

 

[B]

I guess no sort of accuracy is expected of the ammo? Short brass, headspacing on the shoulder instead of case mouth. I am probably coming off as a #### but I'd like to learn. I have tried necking down .40 to run though a .357 conversion for one of my pistols. I had nearly every issue mentioned.

 

[Canuck223]

I guess no sort of accuracy is expected of the ammo? Short brass, headspacing on the shoulder instead of case mouth. I am probably coming off as a #### but I'd like to learn. I have tried necking down .40 to run though a .357 conversion for one of my pistols. I had nearly every issue mentioned.

If the sizing dies are adjusted properly, and the case is headspacing off the shoulder and not just floating in the chamber, held back only by the extractor, then I can't imagine any issue with accuracy.