Lee .358 Mold Sizing to .357

[Hanzy4200]

I am new to .38 special and .357 mag loading, though I have been casting 9MM and .45 boolits for several years. I recently acquired a Lee 158 gr tumble lube 6 cavity mold and a Lee .358 sizing die to match. All was going well, beautiful bullets. Tonight, after a light coat of Alox, I started sizing. Low and behold, the die is sizing the bullets on the low side of .357, as low as .3565 What's the deal? Is my die faulty? Should I go ahead and load them at .357 anyway? They will be fired out of a 4" Ruger GP100.

[str8shot426]

Try them. Worst thing, you would have to scrub some lead.
Lucky you its on the small side. It can be lapped out to .358 using the emery and dowel trick. A site search will find everything you need.

I would post a link, but I am technology challenged and don't know how.

[GhostHawk]

Lee Sizing die's have been shipping on the small side for the last year.

I had a .311 that was throwing .310. I cheated and bought a .314 expecting it to drop at .313 which it did.

My .357 drops right at .356 which works fine for loading 9mm, but not for .357.

My suggestion, try a few unsized, or you can use sandpaper and a dowel to expand that die a bit.

[ShooterAZ]

I had the same problem. Midway replace one, I honed out another using the dowel and fine sandpaper method.

[Char-Gar]

Hummm....I thought that these Lee tumble lube designs were not sized. Just use LLA and fire away. Why else would you use them, if not to skip a step or two?

[jmort]

I would try them. There are knowledgeable people who size their .357 mag cast bullets to .357" with no problems.

[dragon813gt]

The only Lee sizing die I have that was correct was one I bought from RanchDog. All the others were small and had to be increased. You get what you pay for.

[leadman]

The Lee sizing die have also been coming thru pretty rough so polishing it will help this along with increasing the size of the boolits.

Char-Gar, I use some of the TL designs and then coat them with the Hi-Tek coating. They work very well for this. The molds also tend to release the boolits easier.

[kryogen]

they are a little small and rough, so polishing opens it a bit and makes it much smoother.
My 358 die is .3575 with a micrometer. still pretty close, but will open it half a mil while polishing.

And just to make sure, are you using a micrometer? because a caliper is really +- 1 mil, so it's not really good at all for this.

[gloob]

Sizer is easy to open up. No problem.
Hummm....I thought that these Lee tumble lube designs were not sized. Just use LLA and fire away. Why else would you use them, if not to skip a step or two?

Even if you size them, tumble lubing is still easier than anything but a Star!!! But I concur. I have yet to buy a pistol sizing die. If they aren't too big to chamber, they aren't too big to shoot. Any increase in pressure just means I can save a little bit of powder, lol. The day I have a chambering issue, I will buy my first pistol bullet sizer.

[Hanzy4200]

Searching a few forums, I've heard this a couple times. I'm curious whether they are doing so intentionally or not. I have 2 other Lee sizing dies purchased 2 years ago, a .356 and .452, and they are both spot on. I also keep seeing mention of the occurrence of lead "springing" back, or swelling back out .001-.5 a day or two after sizing, and that Lee may (or may not) be adjusting for this.

I have a couple loads worked up and loaded, we'll see how they fair tomorrow. I already e-mailed Midway about it. If they shoot well tomorrow with no leading I will tell them to forget it. If not, I'll just keep it and try sizing some 9MM's to .357 and see how they perform.

[kryogen]

it will take less time to open up the die with sandpaper and a dowel than to email midway about it. plus it will be smoother and glide better.

[bedbugbilly]

Lots of good stuff already said . . . but have you tried them "as cast"? If not, do that as well.

I used to size all of my boolits for 38/357 at .358 with the exception of the Lee TL SWC. I cast a wide variety of weights and profiles and I TL in Alox/Paste wax. Usually, most of them drop anywhere from .357 to .359 depending what mold/design I'm casting. I no longer size anything - I just TL and load. All of them shoot fine out of my 38s and 357s - and I have around a dozen. The same goes for my .357 Handi-Rifle. If you can get them in your casings and they chamber in your pistol . . being a couple thousandths oversize isn't going to hurt a thing unless you have throats that are on the small size that are sizing them down on the way to the barrel.

[kryogen]

I'm sorry to ask again but you did not mention.
Did you measure with a quality micrometer or just with a caliper?

I have noticed that my electronic caliper readings were not worth **** after I got a mitutoyo micrometer. Explained a lot of my problems.
Also, often the bullets are out of round, out of the mold, and even out of the sizer die. No clue why, they vary by half a mil to a mil. So I measure all around... and keep the largest diameter to have a reference point.

Even bullets out of my glock barrel are not perfectly round. Some varies from .3558 to .3562 so I figure that it's approx .356. So I try to feed it 357 bullets.