357Sig. It ain't all that bad!

[Ballistic147]

So, I bought the M&P 40FS last year and ordered a 357Sig barrel to go with it. I've shot 40S&W since it first came out and I really like the Sig as well. I know these can be more difficult to reload than the standard straight wall stuff. For my birthday a few weeks ago my wife bought me the 357Sig dies, however she got the RCBS dies. I had already read that some folks had problems with them getting the shoulder set back far enough. Well, turns out I had the same problems. Turned the sizing die to the point I was scared I would break something when it cammed over and the shoulder was still a good .005" from where it needed to be. Anyway, I ordered a set of Hornady dies and problem solved. Loaded up my first 20 rounds and test fired them today and all was good.

My process was to first run them through a 40S&W die and then the 357Sig die. From there I lightly chamfer it inside of the case mouth and back in the tumbler they go. Hornady uses a 3 die set with an expander die. I set up the expander die to bell the case just enough to get the bullet started. With this I get really good neck tension. The seating and crimping are done with the third die. I set the crimp up to just touch the case mouth. I can all but stand on a finished round and the bullet won't move. My first rounds were built with Hornady 124gr XTP's. I've got some of the Montana Gold 125gr FMJ's on the way and will load up some of those next week.

I've spent a bunch of time reading here forum learning from a lot of the folks here. I must say, the things I e learned here have helped me tremendously. Thanks to all who have posted their knowledge here for guys like me to learn from. Makes this hobby so much easier!

 

[cowboy4evr]

Ballistic 147 , you are absolutely correct . Reloading the 357 sig is really no big deal . I use the LEE 3pc steel die set and added the factory crimp die . Lube the cases one at a time using Imperial sizing wax , takes just a second or two . I have really enjoyed this caliber and I'm not a real fan of semi auto's .

 

[calmex]

I have been wondering about this and this seems like a good place to ask the question; When you shoot .357 Sig out of a .40 by just changing the barrel, is the Point-of-impact anywhere near the sight settings for the .40? Or does that go completely out the window? I have been pondering that question.
Thanks!

 

[fredj338]

I have been wondering about this and this seems like a good place to ask the question; When you shoot .357 Sig out of a .40 by just changing the barrel, is the Point-of-impact anywhere near the sight settings for the .40? Or does that go completely out the window? I have been pondering that question.
Thanks!

I've conv bbls for 3 diff guns, all still shoot poa/poi out to 25yds. Consider fixed sights are identical on most guns chambered in either caliber, makes sense.

 

[Tex1001]

Size your case with a Lee 40 S&W carbide die and then a 357 Sig die to set the shoulder back properly.
I've loaded for 3 pistols for 7 years and never needed case lube. Lee FCD will give consistent crimp
_______________________
I don't have Alzheimer's- My wife had me tested.

 

[Ballistic147]

I have been wondering about this and this seems like a good place to ask the question; When you shoot .357 Sig out of a .40 by just changing the barrel, is the Point-of-impact anywhere near the sight settings for the .40? Or does that go completely out the window? I have been pondering that question.
Thanks!

Mine shoots dead on with either barrel providing I do my job. Like I said, been shooting 40's since they first came out in the early 90's and really like the round. It's funny but I find the 357Sig to be slightly more accurate for me. For just under $100 you can order the factory S&W barrel from Midway and have two different guns. Yes, the Sig ammo is a little more expensive than 40 but since I reload both calibers are cheaper than buying factory 9mm ammo. If you like the 40 I think you'll like the 357Sig just as good.

 

[Ballistic147]

Size your case with a Lee 40 S&W carbide die and then a 357 Sig die to set the shoulder back properly.
I've loaded for 3 pistols for 7 years and never needed case lube. Lee FCD will give consistent crimp.

Since I'm using the Hornady LNL AP most of my dies are Hornady. Not saying they're the best but they have worked well for me. I really like their seating die as the guide sleeve they use lines the bullet up really well. You would almost have to set it on the case sideways to cause a problem.

To size the 357Sig I spray the cases with Hornady One Shot and then run them through the 40 die and then run them through the Sig die to set the shoulder back. After that I do a light inside chamfer on the case neck and run them through the tumbler. The expander die is set to just open the edge of the case mouth enough to get the bullet started without screwing up the shoulder. Don't think there is really any need to crimp at that point since there is no measureable flare once the bullet is seated.

I've read a lot about the Lee FCD but haven't tried one yet. I learned with 9mm that neck tension is key and without that no amount of crimp is going to solve the problem. I was a little worried about loading the Sig but I can say it's pretty easy. Focus on getting the dies set up correctly and it's not much different than any of the straight wall cartridges.

 

[JPucci]

The expander die is set to just open the edge of the case mouth enough to get the bullet started without screwing up the shoulder. Don't think there is really any need to crimp at that point since there is no measureable flare once the bullet is seated.

This is my method as well. I run a very slight flare to get the bullet to sit in the mouth of the case and then no crimp at all so I don't have to worry about reducing neck tension.

My setback testing of this method has shown the least setback of any of the other variations I've tried. No more than .001-.002" setback.

Combine that with AA#9 and the 357 Sig is a consistent, accurate, fun, and safe round to load for me and my M&P Compact.

I shoot them out of a Storm Lake barrel and it's easily more accurate than the same gun with the stock 40 barrel in it.

 

[TAROMAN]

Bullet setback is always a concern with 357 Sig's short neck.
Besides minimum flare as stated, I find the Lee Factory Crimp Die to be useful in securing the bullet.
This is a collet die, same as the rifle ones, not a carbide ring as in the other pistol FCDs.

 

[Rule3]

Here are some good articles on the 357 Sig.

Even though the bullets are 9mm, not all 9mm projectiles are the same. You need ones with more of a driving band specifically for the 357 Sig. Not all 9mm bullets will work. Neck tension is what works here, not crimping.

Real Guns - .357 SIG handloads...controlling headspace

Loading the .357 Sig - MassReloading

 

[fredj338]

I'm spoiled with carbide dies for all my handgun stuff so went Dillon. Since i load on a 550, a perfect fit. I bought a lfcd to try but havent needed it so far.

 

[cellllman]

Headspacing the 357 sig

New to loading 357 sig; most places I have checked the 357 sig head spaces on the shoulder. As stated this makes the set back most important. Now I am impressed by the scientific ways and words to explain this but check out these two pics. M&P 357 sig barrel on left, 40 S&W on right. The loaded rounds are showing exactly the same set. The two barrels are exactly the same save for the interior barrel size. I am assuming this shows that my 357 sig's head spacing is correct in a more un-scientific way but maybe easier to understand? Feel free to correct me if I am wrong!

 

[Ballistic147]

I set my sizing die up using the factory barrel and comparing the headspacing to factory ammo that shot well in the gun. Adjusted the die until the headspace matched the factory ammo and started loading. So far it's worked well.

 

[cshooter]

I'm spoiled with carbide dies for all my handgun stuff so went Dillon. Since i load on a 550, a perfect fit. I bought a lfcd to try but havent needed it so far.

I have to agree, I have been loading the .357 Sig since it first came out. I have never had an issue with chambering my reloads and neither has anyone that has used them. A shooting buddy started reloading the Sig and was having chambering problems with a match grade barrel. He tried mine and no problems. So set up of your dies and headspace is critical, but once set, works every time.
With the Dillon carbide dies, I have never had to lube cases at all. When I first started, brass was difficult to find for the new cartridge, so I made them out of .40's, ( I know it not reccomended, and I would not do that now that brass is so easily found) I could size and neck down the .40's with the Dillon carbide dies in one operation and still not have to lube the cases.