357 mag vs 357 sig

[les hemby]

how do these compare. any info would be great

[Marvel]

As a rule the 357 mag  "tall 38 special" has a wider range of bullets ,much more powerful at its max load and mostly used in revolvers
 The Sig is very accurate for an automatic ,but less power & selection of bullet weights and styles ,its a short necked down case like the old 30 ca. mauser luger round. In 357 mag you can get 110 - 200gr. bullets ,in Sig 115 -147 gr.
Once the top Manstopping round was a 125gr 357 mag. used in revolvers has been pushed aside for high cap. autos which are more accuracy for the new boys " who cant handle recoil & blinding muzzle blast ". Very few 357 mags auto loaders are available , automag , desert eagle, the long round is not good for an autoloader so you would have a revolvers as 98% of you choice , a  S & W 686 used to be a nice rig for all around shooting , also the powder puff 148 gr wad cutter target loads in .38 sp shoot great in any .357 mag are super accurate .. they feel like .22 mags

                 Marvel

[Savage]

Les,
As I'm sure you know, the 357 Sig is a necked down 40 S&W. Because of this, it's short neck precludes the use of the longer, heavier bullets. The intent was to duplicate the ballistics of the 357 Mag round (125gr) in an autoloader.
Stay Safe,
Savage

[Mikey]

Les:  Savage and Marvel have given you some good advice.  The 357 Magnum outshines the 357 Sig in all but one area - the most highly rated 357 Mag Police/Defensive load is the 125 gn softnose/HP at 1425'/sec, which is exactlly what the 357 Sig provides.  In that regard the 357 Sig is an excellent pistol/load combination for Police or personal use.  The 357 Sig also duplicates the 9x23mm or the older preferred loads in the 38 Super caliber.  Were I to choose between the two 357s for personal carry it would be the Sig cartridge.  Were I to have other options I would include the 38 Super with either 9x23mm loads or 38 Super handloads to match (both would provide a 125 gn 9mm bullet at 1425'/sec).

If there is a field application intended then the 357 Magnum takes it hands down.  You can load your 357 Mag to 1330'/sec with 200 gn cast semi-wadcutters and for field work, that load, the 180 gn load or any of the Keith style bullets in 173 or 168 gns, plus the old standby 158 gn load tops the Sig cartridge by a very wide margin.  HTH.  Mikey.

[securitysix]

The .357 Sig was designed to make .357 Magnum ballistics (125 gr. JHP @ 1350 FPS) from a semi-auto with a 4" barrel in the same size gun as the average 9mm/.40 S&W pistols available.  It does that.

The .357 Mag really pulls ahead once the bullet weight goes up.  This is due to case capacity and little else.  

It is true that the .357 Sig is BASED on the .40 S&W case; however, I should note that the .357 Sig is NOT a necked down .40 S&W.  Necking down the .40 results in a short neck, which the .357 Sig is already plagued by.  Also, construction of the .357 Sig brass varies a little in that it is thicker in the webbing.

[les hemby]

thanks for the info. that was what i was wondering. i thought it was pretty much the same with 125 gr factory. i have a 686 6'' for hunting. just bought the sig239 for carry. this should be a very efficient round for its size

[williamlayton]

les-
i have not shot it much, but i recently got the barrel for the 357 in my 239. i like it much better than the .40. course i been under gunned, accordin to these folks, for many years. thank tha lord i never found that out.
blessings

[jamie]

Les, the 239 will serve you very well.  If you reload then the 147 grn will be alot easier to work with, the ogive of the 125's can cause them to be pushed into the case.  Securitysix is right about it NOT being a .40 necked down and it is about as good as it gets with self defence loads, especially since it does reproduce .357 mag balistics with the 125's and with it being necked down it is real easy for that 9mm bullet to fit into that 10mm chamber so it is very unlikely it would jam.

Rest assured you are not undergunned.

[Savage]

Guys,
Sorry to belabor a point, but yes, the 357sig is basically a 40 S&W case necked down to take a 9mm bullet. That's not to say that brass made specifically for the 357 does not differ from the 40 in some internal dimensions, as it does from various manufacturers. Here's some good reloading info: wwwreloadammo.com/357sig.hmt
Stay Safe,
Savage

[williamlayton]

i like shootin tha 357. pretty accurate also-well leastin i aint shotup nobody at tha range. :oops: you boys an a cousin from amarillo turned me onto it. no regrets from this side of tha fence.
blessings

[Marvel]

I think the necked down Sig .357 is more accurate and feeds better than straight wall rounds. My charts show a  124 gr  1330 fps 485 ft lbs SAAMI MAX for the Sig. which can't run with the big dogs ,The .357 Mag  125gr  1738 fps   835 ft lbs Max load , even without , the barrel a few inches longer the Mag. wins.
 The bean counters run target hit percentages and water down loads till all the gang can hit a pie plate at 7 yds ,, thats how we got .40 S&W  and not 10mm as a favorite police round.
The .357 Sig is still a bit of a "wild cat" round , for the guys who like a round that is 60 + years old , with a little history behind it .

         Marvel

[Van/TX]

835 ft lbs ?!!  Holy Cow :shock: .  Any factory ammo close to that?  Thanks........Van

[Marvel]

I have only shot 100 rds of this load. out of 6 & 8 inch barrels

 110 gr bullet  19.8 gr VN110  1872fps  855 Ft LB

 125gr            18.1gr VN 110  1738      835

 140               14.0    NO.9      1349      565

 These are more a hunting round , lots of muzzle blast in shorter guns.
you would have to do a search of factory spec's . In other loads 38 special to 360 ftlb  40 S&W to 525ftlb  10 mm to 680 , 41 mag  1170 ,44 mag to 1345 ,, these are just numbers , Big holes are more important. Once a gun shop employee told a customer" Yeah 1300 ftlb you would kock a deer 15 -20ft if it weighed 200 lbs ' **** OH MY WHAT BULL.