Maybe someone can help me here. I have about 500 Speer Gold Dot .355 Sig bullets (they say Sig on the box) which if I remember correctly are 125gr. I've not been able to successfully reload .357Sig and wondered if I can reload these in my 9mm.

Any comments?

Should work fine. I suspect that there is not much difference between a 0.355" 125gr. ".357 Sig" bullet and a 0.355" 125gr. "9mm" bullet.....

The only problem you MIGHT run in to is if the bullets made for the .357 SIG MIGHT have a slightly thicker jacket and MIGHT not expand as well at 9mm velocities. That's a lot of "MIGHTS" though so I would sure give them a try.
Not to be nosey, but I am, what kind of problems are you having with loading the SIG?

The problem I have is with the crimp. I've done the full range of cartridges with no problem (.45/70, .30-06, etc) and also pistol cartridges (.45acp, .44mag, .40S&W). I have all the dies, plus the tapered crimp dies for the pistol calibers.

Every time I reload .357sig, I get a crimp but I can spin the bullet in the cartridge. I can't get the neck to hold the bullet no matter what I do. I even bought new brass thinking that it was my once-fired that was causing the problem. VERY FRUSTRATING! :mad: I though maybe I was setting the crimp too tight and it was expanding the neck, but even with very little crimp I either have a spinning bullet or I can push it into the case with my thumb.

The die isn't sizing the case neck enough, the expander is too big, or you are flaring the case mouth too much - or some combination of the three.

Examine the case after each step (sizing, expanding, flaring) and see where the problem is.

If you put too much taper crimp in that can actually size the bullet down and cause it to loosen. I had that happen with some .380s. I adjusted the die so that it just removed the bell from the flaring step and the problem went away. As Mike said, check each step. If you set the bullet and it is tight, the expander is not oversized. However, it is entirely possible that you have an expander that is for the .357 Magnum and it is too large for the SIG. The Sig expander should be no bigger than .352 while the .357 Mag expander might be as big as .354, which certainly is not good with the smaller SIG bullet. If your expander is OK and the bullet is tight without any crimp, then you have it narrowed down to too much crimp. Since the SIG headspaces on the mouth you certainly do not want a lot of crimp anyway, even a taper crimp. If your expander is too big, chuck it in a drill and spin it down to about .351-.352 with 220 grit wet/dry sand paper. Also, when flaring, just a hair is enough, just enough so that the base of the bullet will barely fit in the mouth. When I set my bell die I expand the mouth to only about .001 or .002 tops over bullet diameter. Then when I taper crimp, I really don't put in any more than what it takes to press the very mouth back against the bullet. Good luck.

I agree with what both Mike G. and Big Bore said with one small exception. 357SIG does not headspace on the case mouth. Almost all (if not all) 357SIG manufacturers build their chambers considerably longer than the SAAMI case specs. If you do a few measurements on your barrel, you'll see it's impossible for the rounds to headspace on case mouth.

I've been using Rainier plated bullets. They're a lot softer than a jacketed bullet and measure 3.555" in diameter. In the crimp stage, which I separate from the seating process, I don't actually crimp, but rather, I adjust the die to only just get rid of the slight bell I apply. (That's not to say you shouldn't crimp your smaller jacketed bullets).

Keep at it. I've heard of others using Gold Dots with great success.

Have you tried taking the expander out and insert the bullet into a sized case? if there is still no tension then it's the die. If there is tension then it's the expander. If it's the expander, might want to take it out and insert it into a drill and use some fine sand paper to reduce the diameter of the expander ball. I use the Lee dies for my 357 Sig and did not encounter that problem. The reason why they put "Sig bullets" is because the Sig case is longer and therefore requires a shorter bullet than the 9 mm Para. That helps to prevent a consumer from purchasing a box of .355 bullets only to get home and find out after seating they're too long for his magazine. Light weight bullets like 90-100 grs are not a problem though because they're already short. And they are a screamer, too coming out of a 357 Sig.

I was grateful to see all the good info on reloading .357Sig
( I am about to start reloading that caliber for the first time)
but....
Other than MikeG - the replys did not answer the man's question.

He wanted to know if he could use bullets specifically designed for .357Sig ....for reloading normal 9mm (Luger).

Luger's like long tapered nose bullets.

.357 Sig seem to need shorter, fatter, (blunt nose) bullets, with a generous, full diameter: driving band ....to make maximum use of the relatively short neck ahead of the shoulder of the case in holding the bullet firmly in place before firing (apparently a major concern in this caliber).

A typical Luger bullet is NOT a good choice for .357 Sig

Question is:
Are bullets designed specifically for .357 Sig
Adequate for the needs of reloading Luger????
************************************
While I have the attention of .357 Sig reloaders:

Are good quality Hard Cast Lead ("Laser Cast - Oregon Trail)
Bullets OK for .357 Sig in medium velocity range loads?

How about full power (Not overly hot - just within maximum published)?

What Dies do you use?
Lee OK?
Does anybody make a "Factory Crimp Type" die for .357Sig?

renaissance needs to know
renman@concentric.net

I was grateful to see all the good info on reloading .357Sig
( I am about to start reloading that caliber for the first time)
but....
Other than MikeG - the replys did not answer the man's question.

He wanted to know if he could use bullets specifically designed for .357Sig ....for reloading normal 9mm (Luger).

Luger's like long tapered nose bullets.

.357 Sig seem to need shorter, fatter, (blunt nose) bullets, with a generous, full diameter: driving band ....to make maximum use of the relatively short neck ahead of the shoulder of the case in holding the bullet firmly in place before firing (apparently a major concern in this caliber).

A typical Luger bullet is NOT a good choice for .357 Sig

Question is:
Are bullets designed specifically for .357 Sig
Adequate for the needs of reloading Luger????
************************************
While I have the attention of .357 Sig reloaders:

Are good quality Hard Cast Lead ("Laser Cast - Oregon Trail)
Bullets OK for .357 Sig in medium velocity range loads?

How about full power (Not overly hot - just within maximum published)?

What Dies do you use?
Lee OK?
Does anybody make a "Factory Crimp Type" die for .357Sig?

renaissance needs to know
renman@concentric.net
I don't see why the bullets designed for the 357 Sig wouldn't be ok. Should have clarified that. Like someone else already mentioned, expansion of the bullet at a slightly lower velocity might be a concern if you are looking for terminal effects on live targets. Not aware of any "Factory Crimp Type" die for the 357 Sig. Don't have any problems with my Lee die. Haven't tried any cast bullets in the "sig" because mine is a Glock 22 with a 357 Sig barrel.