.357 SIg vs .357 MAG

[Thanis]

Apples to orange comparison or apple to watermelon?

I’m just wondering if people looking at ballistics take into account the barrel sizes these rounds are shot from?

The MAG rounds tend to have larger barrels. If you are looking at the comparison, there would be an advantage if you were looking at a .357 MAG carbine 20” marlin rifle or even a 6” inch S&W revolver vs. .357 SIG standard Glock.

I don’t doubt the MAG is more powerful. Just wondering.

[DefensiveCarry.com]

[HotGuns]

The mag is more powerful and its alot more versatile.
You can use any bullet weight from 110 up to 180 and with the increased length in the barrel you can really get some velocity up if you reload. One of my books has data for a 125 gain bullet moving at a sizzling 1800 FPS. I have used that load and it has exellent accuracy, if you dont mind the sound and the recoil.

The .357 Sig has a much narrower band because it is specifically made to shoot in a semi auto.

THe .357 Sig and the .357 Mag share some common ground, but the .357 Sig load uses velocity that is in the medium range for the Mag.

Even so, the .357 Sig is a step up. While commercial ammo can be pretty sedate, reloads can speed up a bit as long as the gun functions well. Really, though for defensive purposes commercial ammo is plenty good to go.

One thing about the Sig that I have noticed is that it is very loud. When do qualifications shoots at the range, if 20 people are shooting and one or two of them are shooting .357 Sigs, you can always pick them out by the sound.

Some people dont like the recoil of the Sig because its a bit snappier with a bit more muzzle flip but if you are used to shooting bigger calibers it is not an issue.

The Magnum is still the standard that everything else is compared to...the 125 grainers having the nod for the one shot stop.

While the .357 Sig is a bit less, its still a pretty tough platform to use for self defense and from a reloading standpoint, you can use both 9mm bullets and .357 Mag bullets, within reason of course.

I've got a P226 Sig in .357 and I love it.

[Mr. Chitlin]

and from a reloading standpoint, you can use both 9mm bullets and .357 Mag bullets, within reason of course.

Are you sure about this?? Correct me if I am wrong, but I thought that the SIG used .355 diameter bullets (9mm) and the Mag used .357 diameter bullets.

[threefeathers]

357 Sig uses 357 diameter bullets. They are made by Sierra, Montana Gold, Hornady and a few others. I purchased 1K from Montana Gold and they shoot very well.

[HotGuns]

Are you sure about this?? Correct me if I am wrong, but I thought that the SIG used .355 diameter bullets (9mm) and the Mag used .357 diameter bullets.

You are correct.

You're only talking .002 difference. They work well together.
I have made target loads for the .357 with .355 bullets that shot very well.

Some bullets that are .357 actually mike anywhere from .356 to .358, depending on the brand used. Lead bullets are usually sized .001 over.

[Mr. Chitlin]

MG shows their SIG bullets as .355.

Several reloading sites show 357 SIG bullet diameter as .355...

http://www.realguns.com/loads/357sig.htm

Reloading .357 SIG Page

http://en.wikipedia.org/wiki/.357_SIG

[Mr. Chitlin]

Yep, lead usually runs .001 over jacketed.

[HotGuns]

Most manufacturing data shows .357 Sig loads using .355 bullets. I use Accurate Arms reloading date for most stuff, that is what it shows.

[bmcgilvray]

I'm firmly in the .357 Magnum camp. It is capable of more power and versatility.

The .357 SIG is pretty cool though. It's everything that the 9mm's been cracked up to be but isn't.

[Thanis]

Don't want to insult anyone, but I'm really just asking about the ballistics.

As I said, I understand the advantages of the MAG, but for SD barrel sizes, I am having a hard time finding a good comparison.

Gunsmith (gunshop guy) provided a chart to compare a MAG vs SIG. I don't think it was a good comparison. The MAG was shot out of a barrel that was 1 to 1.5 " longer.

Have the different size barrel sizes been considered

[HotGuns]

Click here and have at it.

http://http://www.accuratepowder.com...ard_357cal.htm

The problem as you already noted, is that most manufactures use 6 " barrels for the .357 MAG and 4" barrels for the .357 SIG.

Since the .357 SIG uses semi auto pistol barrels, I doubt you could even find it for a 6 incher.

Some use data for the .357 Mag in a 4" or a 6 " therefore confusing the issue somewhat.

Finding data that uses 4 inch test barrels for each would be a more accurate comparison.

[cvhoss]

While I have no proof, I'd guess that a 6" revolver to a 4" auto would actually be a pretty good comparison. While the auto is giving up 2" of barrel, it gains the advantage of no barrel cylinder gap. The ideal test would be a Model 22 S&W (45ACP, 5.5" barrel) to a 4"barrel 45 ACP auto. I know this isn't 357 Sig / 357 Mag, but it is available to be able to do the comparison if someone owned both types of guns.

Hoss

[Thanis]

Click here and have at it.

http://http://www.accuratepowder.com...ard_357cal.htm

The problem as you already noted, is that most manufactures use 6 " barrels for the .357 MAG and 4" barrels for the .357 SIG.

Since the .357 SIG uses semi auto pistol barrels, I doubt you could even find it for a 6 incher.

Some use data for the .357 Mag in a 4" or a 6 " therefore confusing the issue somewhat.

Finding data that uses 4 inch test barrels for each would be a more accurate comparison.

Thanks both, what I was looking for. The .45 comparison was also an interesting idea.

[NickEMT]

I carry a Sig P-226 in .357 SIG and love both the gun and the caliber. If you're are going to compare the Sig to the Mag, I would have to give the edge to the Mag, it's faster and more powerful. The .357 SIG is my choice for CC because of it's many advantages, it's quick, you can carry a lot of ammo, it hits hard, and it penetrates like the dickens. Check out Doubletapammo Shop for a great selection of hot loads.

[Tom357]

...I’m just wondering if people looking at ballistics take into account the barrel sizes these rounds are shot from?

The MAG rounds tend to have larger barrels. If you are looking at the comparison, there would be an advantage if you were looking at a .357 MAG carbine 20” marlin rifle or even a 6” inch S&W revolver vs. .357 SIG standard Glock...

I realize you apparently have your answer, but I need practice posting as I get active, again, and I figured what better way than in a 357 SIG thread? :) I think, when you are trying to compare 357 SIG to .357 Magnum, that it helps to keep in mind what the goal of the 357 SIG design is. When Federal and Sig Sauer designed this cartridge, they weren't trying to create a platform for a whole range of loads. They were creating a semi-auto LE duty load that would do two things: 1) approach the performance of the venerable 125gr .357 Magnum in a semi-auto standard load - based on a 4" test barrel; 2) exceed the performance of a 124gr 9mm +P in a standard load. I think understanding the intended role of the cartridge helps you make a more informed comparison.

If you go to Federal's site, their 357 SIG and .357 Magnum ballistics are based on a 4" barrel and 4" vented barrel, respectively. If you look at the same bullet in both cartridges, you will be seeing a pretty good comparison for those loads. Remember when you are thinking about real world barrel lengths, that a revolver barrel length doesn't include the cylinder, but a semi-auto barrel length does include the chamber. Think about bullet time and travel in the barrel and how that affects muzzle velocity.

Don't want to insult anyone, but I'm really just asking about the ballistics.

As I said, I understand the advantages of the MAG, but for SD barrel sizes, I am having a hard time finding a good comparison...

I'm not sure what your definition of power is. Performance is dependent on so many things, and can vary significantly from load to load.

9mm +P - Speer 124 gr Gold Dot, 4" barrel - muzzle 1220 fps, 410 ft·lb
357 SIG - Speer 125 gr Gold Dot, 4" barrel - muzzle 1375 fps, 525 ft·lb
.357 Mag. - Speer 125 gr Gold Dot, 4" vented barrel - muzzle 1450 fps, 584 ft·lb
357 SIG - Double Tap 125 gr Gold Dot, 4" barrel - muzzle 1450 fps, 584 ft·lb

In terms of terminal performance, I prefer the Gold Dot or the Ranger JHP's. They deploy consistently and effectively, and at an mv of 1350 fps, penetrate fully without overpenetrating. To me, these are the important performance characteristics. As an EMT, I think modern bullet design has mostly equalized the duty calibers, and it is a matter of preference and marksmanship. All handguns are a compromise of form and function. I think the 357 SIG is a good one.