357 sig?

[Mbaker78]

I have a chance to buy a pistol in this caliber and would like to get some input on reloading for it before I do. I already load 40s&w and 45acp, so is there anything I need to know with this round that will be different? I'd imagine it is at least a little different due to the bottleneck.

[gandog56]

Welll............it's pretty much a .40 cal necked down to 9mm, like a 9mm on steroids. I tend to use the heavier 147 grain 9mm projectiles in this caliber, as the case packs enough oomph to really send that lead flying. BUT.........you will have to use case lube to sized the cases like rifle ammo as they are a bottleneck case.

[Mbaker78]

Even with carbide dies? I haven't looked yet, but I'm assuming they make them. And what about crimping them?

[gandog56]

Even with carbide dies. I know Lee doesn't even have a carbide set for that caliber, only steel. One way around it is to split the sizing into two steps. I use a set from a .40 cal carbide die set to size the outside before the bottlenecked part. Then use the Lee 357 SIG sizer die to final size the bottleneck and properly set back the shoulder. That way I do not need case lube, but it is still just one more step, If if wasn't for nor having to clean the cases up from case lube I wouldn't bother. There is another little problem if you are prepping Speer brass. For some unknown reason Speer decided to make the primer cup flash holes just a bit smaller than usual. A normal size decapping pin is really really tight and hard to squeeze through. If it doesn't hit that hole perfectly centered, you can bend or break the pin. I have never noticed this problem with any other maker of 357 SIG brass. I believe if you have RCBS dies you can get a smaller diameter depriming pin for it.

[DukeInFlorida]

I've waited a while before replying on this one. Was hoping someone else would advise what a pain in the neck it is reloading for this chambering.

I would call this one (357 Sig) an ADVANCED chambering to reload for. No, it's not for beginners or even moderately experienced reloaders.

This one has LOTS of issues that make it a pain and possibly dangerous at worst.

1) The .40 S&W carbide technique is the same one I use. I do that step off line, in an RCBS Rockchucker press.
2) I use a RCBS .40 S&W Carbide die, and asked RCBS for their undersized pin. They sent me a few for free. They were aware of the small flash holes in the Speer brass, and suggested that Speer has been using primer pocket/flash hole tooling made by LAPUA, which is notoriously undersized. Lee does NOT make an undersized pin. I tried turning a Lee pin in a drill motor with emery cloth, and failed in two attempts to get it right. I had a spare RCBS carbide die, and the free undersized pins worked for me.
3) I use a Lee 357 Sig full length resizing die in my Dillon 550b press, in station one. However, I ground off the Lee primer knock out pin, because it would only get pulled out of the internal punch, due to getting stuck in the small Lapua flash holes. So if you use a Lee die for the neck sizing, use the die minus the primer knock out pin, because it controls the interior of the neck when forming the neck resize.
4) Be sure to set the full length resizing die in station one so that the neck gets fully formed to the beginning of taper. This is a critical step, especially because of the short length of the neck. Partial resizing of the neck is dangerous and could result in dramatic "bullet setback".
5) Bullet setback is a known dangerous condition with this chambering. It's one of the reasons that this is NOT a beginner or intermediate reloader chambering. The short length of the neck does NOT provide sufficient normal friction to hold onto the bullets without additional measures taken to assure a very tight grip on the bullet. Even with the suggestions I will provide below, it's critical for you to occasionally check overall length for any rounds that go through your gun without being fired (note, an example of this might be "carry ammo" that you might empty from magazines to allow you to shoot cheaper plinking or practice ammo). I find that even with properly processed (per the suggestions below) ammo, that I often find rounds with bullet setback, and these must be removed from any chance of being fired. Bullet setback will result in extremely HIGH pressures which can blow up your gun!
6) To repeat, the short length of the neck on these cases do not provide sufficient friction to properly hold onto the bullets. Some of the manufacturers use a glue on the inside of the neck, to help hold onto the bullets. It's not practical for a reloader to try and use any sort of glue. DO NOT USE SUPERGLUE!! The aromatics from Superglue will damage and destroy the powder.
7) I use a very slight, and I do mean slight bell mouth on the case mouth. Again, because of the short length of the neck, normal bell mouthing would damage the integrity of the neck. The bell mouthing is a barely there bump, provided to get the bullet started, and facilitate the bullet going in straight, and nothing more than that. I do not use a standard bell mouth on this case. Can't overemphasize this as being one of the things that makes this case more of an expert reloader situation.
8) I use Blue Dot powder (Alliant) for my 357 Sig loads. With all of the reading I did early on for this chambering, Blue Dot was the recommended powder, since it FILLS the case nicely, and prevents any chance of a double charge. A double charge in this chambering will remove body parts, and also destroy your gun! I would recommend Blue Dot as the exclusive powder for the 357 Sig. The only downside for the Blue Dot is when firing the gun at night. The fireball/flash from the Blue Dot is very bright at night. Both you and the bad guy will lose your night vision (when your pupils are the largest) quickly. It's a very bright fireball.
9) After seating the bullet to proper length, check a few to make sure that you are getting consistent seating depth. Bullet setback, even at the time of initial seating is critical, for the reasons previously mentioned.
10) My method for getting better friction between case neck and bullet is to use a Lee "factory crimp die" for the 357 Sig. And, I give this crimp a very tight crimp. Follow the instructions for setting the Lee factory crimp die. I go as tight as I can before risking breaking through the jacket. I use Speer Gold Dot HP 9mm (.355) bullets for my carry ammo, with starting load data for those bullets. I use the Speer reloading data book for that load data, and I would highly recommend that you get a copy of that book, even if only for reloading this chambering, and use that load data. I use a lot of plated 9mm bullets ( Montana Gold, Berry's, etc) for plinking and practice. And, I find that the Berry's hollow point bullets can collapse a bit when seating (the edges of the hollow point nose are soft). The flat nose version are better and give the same point of aim as HP's. I ONLY use 125 grain bullets for this loading, and that was the original design for this round. The 125 grain (compared to the 124 grain) Speer Gold Dot bullets were specifically designed for the 357 Sig, and I would suggest that you do not even try any other bullet weight with the 357 Sig. The plating on the plated 9mm bullets is much thinner than the normal jacketed bullets, and you will have to back off on the Lee factory crimp die, or risk breaking the plating, which could leave the back portion in the chamber or barrel, becoming a "barrel obstruction" leading to a catastrophic loss of body parts and damage to the gun.

So, there's my process, my warnings, and suggestions.

I have been reloading for decades, and am a NRA instructor for reloading. I have had two students ask me to teach them 357 Sig, and I have refused. The reloading class students are all beginners, and the 357 Sig is NOT a beginner cartridge.

So, while I have waited a while to respond, I hope that my comments here have helped you to decide whether or not to buy whatever gun you were looking at.

My current favorite carry gun is a Sig Sauer P229 in 357 Sig.

What I particularly like about the P229 is that I can interchange barrels in the same frame. Sig makes a .40 S&W barrel with is a direct drop in barrel, using the same mags (.40 S&W and 357 Sig). An after market company also makes a drop in 9mm barrel, which mneeds a lighter 9mm recoil spring and guide rod, and requiring Sig 9mm magazines.

So, I have three sets of barrels, and use the same P229 frame for shooting all three chamberings ( 9mm, .40 S&W, and 357 Sig) While I have other guns in .40 S&W, and 9mm - the favorite 9mm is the M9 Beretta, I find myself using the P229 platform for "hand memory" when it comes to practicing for self defense.

I use nickle plated cases (mostly Speer) for all carry ammo. The nickel cases resize fine, and cause no issues whatsoever with any of the tooling. I avoid any chance that the brass cases would get tarnished/corroded as carry ammo. I don't want anything to cause any bullet setback, or chambering issues for the carry ammo. Police officers carry only nickel plated ammo for that reason, despite the chambering ( .40 S&W, 9mm, 45 ACP, etc.)

For practice and plinking ammo, brass cases are fine. But for carry, use the nickel plated cases. You won'e need many of those, a hundred or so will be enough. I make up enough nickel plated carry cartridges to fill three mags, plus an extra set, which I swap out when I find a cartridge with any bullet setback.

[gandog56]

Well, I don't really find them harder to reload than any other bottleneck cartridge. Same steps have to be taken unless you do my two step sizing. I actually like the round in my gun better than a 9mm. And I have one pistol that fires both it and 9mm....AND .40 cal. (Different barrels, springs, and slide for each.)

I have the same problems when I reload 7.62X25 or even worse, 7.62 Nagant.

[Mbaker78]

This gun actually comes with the 40s&w barrel as well. So that'll likely be the one I use most, but I like to be able to load for everything I shoot. Maybe I just won't shoot 357sig as much ;)

I remember reading a while back about the flash hole problems, now that you mention it. I run all of my brass through a deprimer first, so I'll just have to keep an eye out for Speer cases.

I do thank you all for your input, it's looking like these will likely get loaded the same way I do with 223 and 300aac.

[gandog56]

This gun actually comes with the 40s&w barrel as well. So that'll likely be the one I use most, but I like to be able to load for everything I shoot. Maybe I just won't shoot 357sig as much ;)

I have more .40 cal brass than any other caliber, including 9mm. I have a whole pile of 357 SIG too, since I have two pistols that shoot that.

[Mbaker78]

I haven't really shot my 40 as much this year as last year, usually just a couple magazines worth each range trip, to stay familiar with it

[gandog56]

I don't shoot either of my .40's ever since I got my Mechtech 10mm CCU. It's just so fun and I am using the same bullets I also use for .40 cal reloads on them.