Anyone here reload for .357 SIG

[1sailor]

I'm looking for another SIG and want to get one in .357 SIG. It's a spendy round off the rack but I can reload for not much more than for 9mm. I load for several other calibers but they are all straight wall pistol cartridges. How often do you really have to check OAL? Is it something that needs to be done each time you reload a case or can you stretch that out? Any quirks particular to the round? This will be my first experience with a bottleneck cartridge.

[rwsmith]

Trim the cases and you won't have to worry about stretching for a good while. Check them every now and then. I'm not sure how much .357 Sigs stretch. Rifle cartridges are good for about five heavy loads then they should be checked. It also depends on how hot your loads are.

Or just measure them and trim any that are close to the limit or excessive. Check them to learn how many firings it takes to stretch them.

I made a cheap, fast method of trimming by chucking a Lee tool into my drill press. Trim like gangbusters.

[Groo01]

Groo here
This is a super secret 357sig loading.
Get a set of dies, then get a 40S&W carbide sizing die and remove the guts.
Pre size the case with the 40 die[no lube needed] then adj the sig die
To neck size .
Big secret worth much wampum and will reduce stress greatly.
PS. The 357sig headspaces on the shoulder not the case mouth
like many books say.[ look at european drawings not sammie]
If your shoulder is right the round should work in most any gun.
Also the 9mm bullet often will not work because of the short. neck.
The flat nose one seem to work though.

[woden]

I use 40 s&w brass, just to start my experiments.

Glock 32, Lonewolf barrel
Lee mould 356-120-TC

Results:

bullseye 4.3Gn
AV Vel. 1013 f/s

bullseye 4.9Gn
AV Vel. 1159 f/s

bullseye 5.5Gn
Max Vel. 1310 f/s <-- chrony battery died, so i just have 1 max

Hope this help

Regards

[1sailor]

Thanks for the replies guys. Groo, I have a ton of 135gr RN and 147gr FP bullets that I use in my 9mm's. Are you saying that I may not be able to use these when reloading for the sig round? What about the Hornady XTP's in 125gr and 147gr?

[Tom S.]

Originally Posted by 1sailor

Thanks for the replies guys. Groo, I have a ton of 135gr RN and 147gr FP bullets that I use in my 9mm's. Are you saying that I may not be able to use these when reloading for the sig round? What about the Hornady XTP's in 125gr and 147gr?

Lyman's shows loads for a 147gr round nose, so I don't know why a FP won't work. As with any round, start at the lowest recommended charge and work up. And if they can load a 147 gr, a 135gr should work too, provided you can find info for it.

[AlHunt]

I have just started reloading for the 357 SIG. I can tell you that the bullet you use needs to have enough straight body for the case neck to hold onto. A typical RN bullet starts to curve in too soon. Look at some bullets recommended for 357 SIG and you should see what I'm talking about.

The only other accommodation I've made is to seat and crimp in separate steps. For now, anyway. Maybe once I get more behind me, I'll go back to doing both in one step.

[mtnwinds]

Originally Posted by 1sailor

Thanks for the replies guys. Groo, I have a ton of 135gr RN and 147gr FP bullets that I use in my 9mm's. Are you saying that I may not be able to use these when reloading for the sig round? What about the Hornady XTP's in 125gr and 147gr?

Many (not all) 9mm bullets have a taper from the base to the nose that will not allow a tight grip by the357 Sig case neck, thus increasing the possibility of 'set back' when chambering. The 9mm case is a tapered case, not straight.

Safest bet is to check with the mfg regarding suitability of their 9mm bullets for the 357 Sig or just buy bullets designed for the 357 Sig.

Please be aware that if you use 40 S&W cases to make 357 Sig cases, you may end up with a neck that is shorter than the already short 357 Sig.

You might consider buying a Wilson case length/headspace gage if you intend to reload your brass. Cheap insurance that will help prevent a lot of problems.

Some will say they have fired many thousands of round using reformed 40 &W Sbrass. 357 Sig brass is around $40/1000 which negates any potential savings by using 40 S&W brass.

Factory 40 S&W brass was originally designed to contain 35,000 psi while 357 Sig brass was designed to contain 40,000 psi, or 2 1/2 tons more.

[mtnwinds]

Originally Posted by 1sailor

Thanks for the replies guys. Groo, I have a ton of 135gr RN and 147gr FP bullets that I use in my 9mm's. Are you saying that I may not be able to use these when reloading for the sig round? What about the Hornady XTP's in 125gr and 147gr?

Many (not all) 9mm bullets have a taper from the base to the nose that will not allow a tight grip by the357 Sig case neck, thus increasing the possibility of 'set back' when chambering. The 9mm case is a tapered case, not straight.

Safest bet is to check with the mfg regarding suitability of their 9mm bullets for the 357 Sig or just buy bullets designed for the 357 Sig.

Please be aware that if you use 40 S&W cases to make 357 Sig cases, you may end up with a neck that is shorter than the already short 357 Sig.

You might consider buying a Wilson case length/headspace gage if you intend to reload your brass. Cheap insurance that will help prevent a lot of problems.

Some will say they have fired many thousands of round using reformed 40 S&W brass. 357 Sig brass is around $40/1000 which negates any potential savings by using 40 S&W brass.

Original pressure spec for the 40 S&W was 35,000 psi and the 357 Sig was 40,000 psi, a difference of 2 1/2 tons.

[1sailor]

Okay thanks. Too long of a taper makes sense. I was having difficulty in trying to figure out why some 9mm bullets wouldn't work correctly. Also explains why Groo1 has better luck with flat nose bullets.

[Mtnfolk325]

I just happen to have approximately 1,300 1x .357 Sig brass, they will go to anybody for the freight cost.

[gen3guy]

Originally Posted by Groo01

Groo here
This is a super secret 357sig loading.
Get a set of dies, then get a 40S&W carbide sizing die and remove the guts.
Pre size the case with the 40 die[no lube needed] then adj the sig die
To neck size .
Big secret worth much wampum and will reduce stress greatly.
PS. The 357sig headspaces on the shoulder not the case mouth
like many books say.[ look at european drawings not sammie]
If your shoulder is right the round should work in most any gun.
Also the 9mm bullet often will not work because of the short. neck.
The flat nose one seem to work though.

Ditto. Do what Groo says here. You will not be sorry. I've been using Berry's 124 gr. plated FN with much success.

[AlHunt]

Originally Posted by Mtnfolk325

I just happen to have approximately 1,300 1x .357 Sig brass, they will go to anybody for the freight cost.

Pick me! Pick me!

PM inbound. I'd be happy with half of it if anybody else wants the other half ...

[fredj338]

Originally Posted by 1sailor

Thanks for the replies guys. Groo, I have a ton of 135gr RN and 147gr FP bullets that I use in my 9mm's. Are you saying that I may not be able to use these when reloading for the sig round? What about the Hornady XTP's in 125gr and 147gr?

Not likely. The biggest issue with the 257sig is the short neck & OAL. Most RN 9mm bullets will seat too long in the short neck. In my exp, for bullets over 100gr, you will need a truncated cone to get the OAL right.
I use Dillon dies, the only carbide available. IF you load on a ss press, then you will need a flare die form someone else. The alternative is lube the cases or size/decap in a carbide 40 die. The shoulder can then be setback using 357sig sizer w/o lube & be fine. Just adds another step. Since money can be made & time can not, the Dillon dies are worth it for me.
IMO, just buy the correct brass. It is cheap in once fired form so making them form 40 seems pointless. Someone may even trade you 40 for 357sig, maybe, but 40 is pretty easy to just pick up at ay local range.

[Groo01]

Groo here if you crank up your Googlefu and search "reloading 357sig"
you will be blind before you read them all.
+1 on once fired brass.
Another Secret , the sig seems to like the 147gr flat nose bullets.
Cast ones go over 1200fps with out much trouble.

[27 Man]

.357 Sig has a short neck and it is imperative that your resizing die reduces the diameter of the neck enough to ensure that the neck will have a good firm grip on the bullet. When that cartridge is going up the feed ramp, you don't want any setback on the bullet. The round is already a relatively high pressure round and you don't want to increase that with setback. I have loaded pistol cartridges for 40 years and the .357 Sig has given me the most challenges.

[Tex1001]

Originally Posted by Groo01

Pre size the case with the 40 die[no lube needed] then adj the sig die To neck size.

I use Lee dies (40S&W carbide and Lee steel 357 Sig) also. Another Real time saver:
I don't have to lube cases for the neck sizing die, the steel is very hard. I've loaded over 1100 cases and the die shows no wear.
The Lee Factory Crimp Die in 357 Sig will eliminate crushed shoulders.
I wouldn't use plated bullets unless they are plated extra thick.
Stay completely away from Rem Golden Sabre bullets.
_______________________
I don't have Alzheimer's- My wife had me tested.

[NJM15]

Originally Posted by 1sailor

I'm looking for another SIG and want to get one in .357 SIG. It's a spendy round off the rack but I can reload for not much more than for 9mm. I load for several other calibers but they are all straight wall pistol cartridges. How often do you really have to check OAL? Is it something that needs to be done each time you reload a case or can you stretch that out? Any quirks particular to the round? This will be my first experience with a bottleneck cartridge.

To start with using the .357 sig die (I use Lee) you would have to lube ,if you run them through a .40 S&W die first you don't have to. That will do the base , the sig die will do the neck don't over flair the neck there is not much area holding the lead, and I use a crimp die to finish. I have done hundreds that way with good results. good luck be safe