[Tony L]

I load for 10mm and 45ACP. The 357 sig is new. I have found on Western powder
manual the load they have is 12 - 13 grains of Accurate #9 with a 125 grain bullet.
I would like to load this round on the warmer side. Is this a good place to start with this load?
Thank you

 

[DansSIGs]

OP,
Platform is-
TupperWare platform?
SIG Classic P Series?

Accurate Arms (TN) & Accurate (MT) powders are NOT interchangeable.
Accurate (MT) powders are faster burning than Accurate Arms (TN) powders.

COAL length will need to be at max length 1.135" to get 13+ grains of A#9 in the 357SIG case.

Do a "plunk" test w/ a dummy round to ascertain the maximum COAL.

Start at the 12gr load & work up accordingly.

If you attempt to use Accurate #7,download by a couple grains & work up.

A chronograph will tell the tale when you reach the optimum load.


Correction-
Accurate Arms powders were distributed from Tennessee...not Virginia.

Now that Hodgdon bottles Accurate Powders...who knows what you'll get...per lot.

 

[LEEEAGLE]

I don't have any experience with A#9, I have been using HS-6 @9.5gr. And VIT N350 @8.2gr (only when short of the hs6) I try and keep the 350 for the. 45ACP and .40SW. When I get A#7 I load to 11.5gr. But prefer the HS-6 For my 124 and 147gr hp loads. I am sitting on quite a bit of 115gr XTP bullets left over from when I used to load 9mm, and have been thinking about loading them for the .357sig, but haven't checked the math yet

 

[Tony L]

Sorry the platform is a Sig P320 full size.

 

[ARgon]

I don't have any experience with A#9, I have been using HS-6 @9.5gr. And VIT N350 @8.2gr (only when short of the hs6) I try and keep the 350 for the. 45ACP and .40SW. When I get A#7 I load to 11.5gr. But prefer the HS-6 For my 124 and 147gr hp loads. I am sitting on quite a bit of 115gr XTP bullets left over from when I used to load 9mm, and have been thinking about loading them for the .357sig, but haven't checked the math yet

Would like to hear what you come up with on the 115grain.

 

[LEEEAGLE]

Would like to hear what you come up with on the 115grain.

I haven't done anything yet. But I would be using the same powders as above, that is what I have.
But basically from my experience, the 115gr will need about .5-1grain more powder. I really don't have much interest in 115 for the .357, if I could get them to run accurately @1450-1500fps then I would be more inclined to use them

 

[jkallner]

I don't load hot 357 Sig rounds so my formula wouldn't do you much good - the only suggestion I have is to resize the brass with a 40 S&W die before loading for the 357 Sig. It's not mandatory, but I found the machine works much smoother if the case doesn't have to be resized and de-primed. I run all my brass through to resize and de-prime and change 357 Sig and reload normally as I would a straight wall case. Good luck!