.357 SIG powder and bullets recommendations

[Guns4545]

Gonna start reloading 357 SIG for my Glock 32 and was wondering what y'all recommend for powder and FMJ bullets. 125gr is what I'm thinking. BTW I'll be using lee dies.

[SouthernCoyote]

As someone who recently started loading .357 SIG for my XDm, a few tips to help you out. The LEE dies are excellent for the SIG, they are the correct dimensions. Make sure you go ahead and get you a .40 LEE carbide die as well to size the body first, then the SIG die to shape the shoulder. This will keep you from having to lube the cases and clean them again. Also get the LEE factory crimp die because trying to crimp and seat at the same time in the SIG can be a hard thing to get right, especially if you use multiple type projectiles.

For powder, Longshot & Power Pistol give you magnum like performance as the cartridge was designed to do (ballistics of a 125 grain .357 Magnum in a semi auto platform. Both powders have the velocity and accuracy down pat. Also, AA#9 is a great powder as well. Many use it due to the fact it fills the case almost completely which keeps the bullets from setting back in the event that neck tension should fail. I use all three powders and love them all. AA#9 will give you the least amount of velocity, but is still a great powder. All 3 powders in my trials burn clean.

For projectiles, Xtreme 124 RNFP work very well and are cheap enough you can plink with. They tend to be pretty accurate too. Speer 125 grain Gold Dot (SIG profile) work very well too! They are accurate and its what LEO use every day and depend on for their lives. The Hornady 124 grain XTP work very well just like the others. They are accurate, even more accurate in my gun than the Speer. Something I dealt with when loading that I'm not sure as to why it happened is belling the cases just right... The Xtreme didn't need any belling at all, though I belled just a tad bit.. the Speer required a good bit of belling, or they would seat off center and crush the cases.. the XTP seated very similar to the Xtreme and didn't need much belling at all. It was tough to find the happy medium when setting my powder die on the Dillon to where they all did well without losing neck tension or being to tight to seat properly. Also a lil tip with the LEE dies, since I have them set up on my Dillon, I took a fine tip Sharpie to mark each position with for the different projectiles so switching between them is easier to find the right position to return to the correct seating depth for each one.

Hope this helps. The SIG is a fun round to shoot, POA at 10-50 yards is a blast... aim and send it!

[Guns4545]

As someone who recently started loading .357 SIG for my XDm, a few tips to help you out. The LEE dies are excellent for the SIG, they are the correct dimensions. Make sure you go ahead and get you a .40 LEE carbide die as well to size the body first, then the SIG die to shape the shoulder. This will keep you from having to lube the cases and clean them again. Also get the LEE factory crimp die because trying to crimp and seat at the same time in the SIG can be a hard thing to get right, especially if you use multiple type projectiles.

For powder, Longshot & Power Pistol give you magnum like performance as the cartridge was designed to do (ballistics of a 125 grain .357 Magnum in a semi auto platform. Both powders have the velocity and accuracy down pat. Also, AA#9 is a great powder as well. Many use it due to the fact it fills the case almost completely which keeps the bullets from setting back in the event that neck tension should fail. I use all three powders and love them all. AA#9 will give you the least amount of velocity, but is still a great powder. All 3 powders in my trials burn clean.

For projectiles, Xtreme 124 RNFP work very well and are cheap enough you can plink with. They tend to be pretty accurate too. Speer 125 grain Gold Dot (SIG profile) work very well too! They are accurate and its what LEO use every day and depend on for their lives. The Hornady 124 grain XTP work very well just like the others. They are accurate, even more accurate in my gun than the Speer. Something I dealt with when loading that I'm not sure as to why it happened is belling the cases just right... The Xtreme didn't need any belling at all, though I belled just a tad bit.. the Speer required a good bit of belling, or they would seat off center and crush the cases.. the XTP seated very similar to the Xtreme and didn't need much belling at all. It was tough to find the happy medium when setting my powder die on the Dillon to where they all did well without losing neck tension or being to tight to seat properly. Also a lil tip with the LEE dies, since I have them set up on my Dillon, I took a fine tip Sharpie to mark each position with for the different projectiles so switching between them is easier to find the right position to return to the correct seating depth for each one.

Hope this helps. The SIG is a fun round to shoot, POA at 10-50 yards is a blast... aim and send it!

Thanks for the help. Really appreciate it. Gonna use Longshot and pick up some xtreme 124gr rnfp as well as Speer 125gr Gold dots from Wes. Where did you find brass? Wes is out of stock now. Should I go with starline?

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[SouthernCoyote]

I bought all the brass he had left a lil while back LOL. There seems to be a drought with the SIG brass at times like now. If you go with Starline, at least you will have all same head stamp. Starline is good stuff in my experience. Keep in mind, if you get some mixed brass, there are regular sized flash holes and small Lapua sized flash holes. I always decap with my Mighty Armory decapping die and Lapua decapping pin before I stainless wet tumble them. I remove the decapping pin from my 40 & 357 sizing dies so that there is no issue with sizing them since they are already decapped.

[Guns4545]

I bought all the brass he had left a lil while back LOL. There seems to be a drought with the SIG brass at times like now. If you go with Starline, at least you will have all same head stamp. Starline is good stuff in my experience. Keep in mind, if you get some mixed brass, there are regular sized flash holes and small Lapua sized flash holes. I always decap with my Mighty Armory decapping die and Lapua decapping pin before I stainless wet tumble them. I remove the decapping pin from my 40 & 357 sizing dies so that there is no issue with sizing them since they are already decapped.

I use the Lee universal decapping die for everything then wet tumble. Will the Starline brass have the correct size flash hole for the universal Lee decapping die?

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[SouthernCoyote]

Not sure what size the starline is, don't have any in 357 SIG. I've used it in a few rifle calibers though. If the holes are the small Lapua size, you can probably punch through them, but the easiest thing would be take the pin out, put it in a drill and whittle it down with some sand paper til if fits in the tiny holes just barely. I did that to my LEE as well and if you break a pin after you've done that, then something is wrong somewhere besides the pin. I've decapped thousands of rounds of crimped primers with it and no issue at all. Just changed over to the MA die since I use it on a separate set up now. Still use the LEE on my turret set up for brass prep.

[Guns4545]

Not sure what size the starline is, don't have any in 357 SIG. I've used it in a few rifle calibers though. If the holes are the small Lapua size, you can probably punch through them, but the easiest thing would be take the pin out, put it in a drill and whittle it down with some sand paper til if fits in the tiny holes just barely. I did that to my LEE as well and if you break a pin after you've done that, then something is wrong somewhere besides the pin. I've decapped thousands of rounds of crimped primers with it and no issue at all. Just changed over to the MA die since I use it on a separate set up now. Still use the LEE on my turret set up for brass prep.

Is this the correct MA for small lapua size flash holes? I want to get one for my Lee singe stage. https://www.mightyarmory.com/collect...12346027802702

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[SouthernCoyote]

That is the correct one. Very good unit, tough as it gets.

[Guns4545]

That is the correct one. Very good unit, tough as it gets.

Awesome. I'll pick one up. Any other tips? Thanks again for all your help.

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[SouthernCoyote]

http://www.theshootersbox.com/357-Si...n_p_24919.html

Grab you one of these. I prefer these case gauges for the SIG. It has a 3 step indicator which will give you the minimum sammi spec at the first step and maximum sammi length at the middle step for the brass/loaded round. The third step is the maximum headspace for checking headspace on fired brass to see if your chamber is over spec according to the fired brass. These will let you know if your shoulder or trim length are not correct. Save tons of headaches when getting everything together before loading up and shooting.