reloading 357 sig ??

[kennedy]

getting into reloading 357 sig, already ordered a Lee die set, do I need a crimp die? also do I need a L Wilson cartridge case gauge to make sure head space is correct? also I can`t find any 125 gr .355 sig bullets, can I use 125 gr 9mm .356 bullets?

 

[N555]

Generally all your 125gr .355'' bullets are "357sig" bullets. 124gr .355'' bullets are for 9x19.
The difference being the 125gr bullets hold together at 357sig velocity better than traditional "9mm luger bullets".
When loading FMJs it doesn't matter, just pick a weight.
My hot sten gun ammo I'll use 125gr HPs because I'm exceeding 357sig velocity with a hot load of slower powder in it's 9 inch barrel.

 

[WrongHanded]

I have a set of Lee dies. With the resizing die touching the shell holder, it does well enough that I just don't bother with the Wilson case gauge anymore.

The FCD is something I use, but that under normal circumstances really doesn't do anything. If it's set to crimp too much, it will crush the bullet, but the brass will bounce back, ruining neck tension. I have found that I prefer to simply not flare the case mouth any more than is absolutely necessary to get the bullet just barely into the mouth, then hold it and ride the ram up to the seating die (moving my fingers before I pinch them). I also chamfer the inside of the mouth just a little with new brass to aid in this process. Then I find crimping really isn't necessary as the neck tension is still good.

You may want to get a 10mm/.40S&W carbide resizing die. Then you can resize the body of the case first, and not need lube when you switch to resizing the neck. No lube makes life easier, and means there's no chance of getting any inside the case neck, which if not removed will reduce friction and increase the chance of bullet setback.

 

[kerreckt]

I found that a Sheridan cut away ammo gauge to be very useful when reloading the .357SIG. It allows me to get the shoulder "bump" perfect. I little pricey but worth it. Best wishes!

 

[kcofohio]

I have only used my barrels as a cartridge gage for the 357 SIG.
I would avoid most round noses, as you don't want the taper of the bullet in the neck. Only the bearing surface.
Like @WrongHanded , I like to put a slight chamfered on the case mouth. Only cast bullets do I flare the mouth for.

 

[Blue68f100]

Use your barrel the chamber gauge. I did a test with the LFCD it hurt accuracy, so it went in to the drawer. With the short necks on the 357 sig neck tension is critical. I use a expander that gives me just enough flare (mouth only) to keep from shaving the bullet. I also use a powder that gives me a compressed load to help prevent bullet set back. You need to use a bullet that is made for the 357 sig. Most 9mm the ogive is too long and ends up in the neck, so you have little to no neck tension.

 

[kennedy]

ok, thanks, I do have a .40 die, so thats a good idea, how do you use the barrel as a gauge? I am using it in a sig 226 .40 with a sig 357 barrel. has any one found a 9mm bullet that will work? or a source for 357 sig bullets?

 

[kcofohio]

ok, thanks, I do have a .40 die, so thats a good idea, how do you use the barrel as a gauge? I am using it in a sig 226 .40 with a sig 357 barrel. has any one found a 9mm bullet that will work? or a source for 357 sig bullets?

Here's a good explanation
https://www.thehighroad.org/index.p...rel-find-a-max-o-a-l-with-your-bullet.506678/

 

[2 Horse]

I use X-Treme .355 124gr FP over a load of Longshot, pushes them 1370 fps. Don’t think a plated bullet will take a hole lot more speed than that.

 

[Blue68f100]

RMR match winners are what I use for 357sig. A excellent bullet at a great price.

 

[WrongHanded]

RMR match winners are what I use for 357sig. A excellent bullet at a great price.

Also what I use, at 1.140" OAL. Works great for me with a max charge of Power Pistol.

 

[kennedy]

RMR match winners are what I use for 357sig. A excellent bullet at a great price.

went to their web site and they have a 9mm 124 gr fmj truncated cone flat nose, is this what you are using?

 

[WrongHanded]

went to their web site and they have a 9mm 124 gr fmj truncated cone flat nose, is this what you are using?

I don't know about him, but it's what I'm using. I've shot over 2000 of them in .357 Sig at this point.

 

[Blue68f100]

went to their web site and they have a 9mm 124 gr fmj truncated cone flat nose, is this what you are using?

These are what I'm using. https://www.rmrbullets.com/shop/bul...gr-rmr-truncated-cone-flat-point-matchwinner/

These also work https://www.rmrbullets.com/shop/bullets/pistol/9mm-355/9mm-124-gr-rmr-jhp-mpr-nuke/

 

[Yamifrk]

Rmr bullets work well in the 357 sig AA9 as a compressed load, I chamfer the case as well.