Lubeless Loading the 357Sig

[Clovis]

I read in the Midway website that reloaders load the 357 sig w/o lubing the case by using 2 sizing dies - a 40SW carbide sizer, then the 357 sizer.

I was wondering if anyone has experience with this and does it really work? Won't it damage the steel 357 sizer die since the case is unlubed?

Any feedback would be highly appreciated....

[Leftoverdj]

Sounds like more work than it's worth with some risk of pushing the shoulder back.

[Bullet94]

How could you use a 357 sizer when the 357 Sig is 9mm?

[enstorm]

It works fine. It is not more effort than it's worth. It won't add to the risk of pushing shoulders back. The .40 sizing die, however, must be carbide. I always reload my 357 Sig rounds this way, an RCBS .40 carbide sizing die followed by a Lee steel sizing die for the neck/shoulders. You don't need to lube at all at any point in the process, which is what really saves time if you clean lube off finished rounds. The risk of pushing the shoulders back is the exact same as you run using only 357 dies. That's because the .40 sizing die doesn't have shoulders and can't deform the brass that way. Only the 357 die can do that. Some people run the brass through the .40 sizing die and then through a 357 Sig neck sizing die instead of a full length die, sort of like prepping fire-formed rifle brass. In fact, I don't know why you couldn't do away with full-length sizing altogether with the 357 Sig and just neck size the brass, so long as you use it only in the same pistol--?

[Leftoverdj]

How could you use a 357 sizer when the 357 Sig is 9mm?

Not enough difference to make a difference, Bullet. Brass thickness varies more than the difference between bullets. The .357 sizer is used to neck size only. I usta know a fellow who loaded everything in sight with a set of .38 Super dies. 9x19, 9mm Bayard-Bergmann, .38 Super, .38 Special, .357 Mag all went through the same set of dies. Some of them came out a little Coke bottle shaped, but they all worked, and worked pretty good.

[Bullet94]

Leftoverdj

I should have said - Why use a 357 die for a 9mm (357 Sig)?

Wouldn’t you want more neck tension instead of less especially in 357 Sig?

[Zekewolf]

Bullet: You sure you understand what .357 Sig is? The .357 Sig die accommodates a .357 Sig case, which is a .40 necked down to 9mm. He's not using a ".357 die" to size a 9mm.

[Bullet94]

Zekewolf

I understand what the 357 Sig is.

I was referring to the original question by Clovis Quote – “I read in the Midway website that reloaders load the 357 sig w/o lubing the case by using 2 sizing dies - a 40SW carbide sizer, then the 357 sizer."

When Clovis referred to a 357 sizer I thought he was talking about a 357 Magnum die (.357) not a 357 Sig die (.355). My mistake.

[Clovis]

Thanks for the info guys. Well after reading all your posts, I got the nerve to try it borrowing my friend's 40SW die. I did 2 things, one of the fired 357 sig rounds was loaded the usual way using lube and just the 357 sig sizer. THe other round was loaded w/o case lube using 2 sizing dies. I compared the finished rounds with a factory 357 sig.

Results : The two step sizing method produced nearly identical dimensioned rounds to the normally loaded 357 sig. Both were within 0.05 mm of the factory round, the one loaded with 2 sizing dies being closer to factory specs.

Well the only issue is, does sizing unlubed case on a steel die damage the steel die? Since I load with Lee dies, I gave the Lee factory a call and they had no issues with it. They said the lube for sizing is to prevent the case from getting stuck in the die and NOT to prevent damage. They mentioned the Lee die is strong enough for lubeless sizing.

Well I'm loading 357sig in two steps from now on. Goodbye case lube!!!!!

[Unclenick]

Clovis,

If you are at all concerned about wear and/or sticking in the steel Lee die, take the following two steps:

1.) Get a Dremel tool or similar device and a bullet-nose felt bob and some Dico stainless steel grade polishing compound. Load up the bob with the compound and polish the inside of the Lee die. This is easiest if you have a lathe so you can turn the die at about 60 RPM while your run the spinning bob in and out. If you don't have a lathe, just roll the die back and forth on a table with one hand as you follow along with the Dremel in the other, going in and out. Every few rolls back and forth stop and turn the die about a third of a turn in place so you get even coverage.

2.) After polishing, clean and degrease with Gun Scrubber or other solvent strong enough to remove any wax base from the polishing compound, then treat the die with a permanent lube. You can soak it 72 hours in Sprinco Plate +. You can warm it and spend about 20 minutes working Shooter's Solutions MolyFusion oil into it with a felt bob. You can soak it for about three weeks in a 10% solution of 20W and Advanced Lubrication Technologies' Motor Silk. You could warm it and work in Microlon Gun Juice by wetting it, sizing a case, wetting it again, and then running the case in again, etcetera, through about 5 cycles.

All the above permanent lubes will make the die leave a smoother finish and require less forming pressure, hence less wear to either the die or the cases going through it. I used the polishing and Plate+ combination on a Lee cast bullet sizing die I use to take .314 diameter cast bullets down to .308. They come out of the die with the surface so glass smooth they look like they were wet with oil. No lube needed.

The MolyFusion oil is another good bet here. It turns the surface slightly yellow gray, forming waxy feeling permanent coating on the surface. Like Plate+, they treat barrel bores with this stuff to reduce fouling, so it is more than tough enough for brass sizing. It is the closest thing I know to applying a home non-stick coating to something, but micro-thin, so it won't significantly affect dimensions (I don't actually recommend this treatment for cooking utensils, by the way—I haven't a clue as to its ingestability).

The Microlon product is the oldest of the bunch. Also a bore treatment, it works best on warm metal, leaving a PTFE coating on and in the surface and in the grain boundary space of the metal surface.

The motor silk applies Boron Oxide which, like Microlon, as a motor treatment is shown to significantly reduce metal wear products appearing in used motor oil. The reaction is slow at room temperature. Even at motor temperatures it takes several days of normal driving to do its thing. You need patience, but the claim is its coefficient of friction is lower than any other permanent lube. I've just started playing with this stuff, so I don't know it for a fact yet. Like Plate+, it is a government laboratory research product licensed to the commercial vendor.

Nick

[Zekewolf]

Clovis: The major sizing part of the job is being done with the .40 carbide die. The .357 Sig die is only bumping the shoulder and neck-sizing. You won't wear out your steel dies, using that technique!

[Clovis]

Thanks for all your thoughts. I am impressed with the quality of ideas in this forum. All ideas well taken and I hope to share my experiences to help you out someway.

thanks again !!

[skeet47]

I use the dillon 357 sig carbide die and eliminate all that trouble.

[caz223]

It's easy.
Step one: Buy carbide sizing die from dillon.
Step two: Buy LEE factory crimp die in 357SIG.
Step three: Buy a can of hornady one shot.

Dump your brass into an akro-bin, spritz with one shot. SPARINGLY. As in, less than a second from several feet away.
Load in your progressive.
No need to tumble your brass afterwards.
Done.