STI Eagle now in .357 SIG

The STI Eagle 5.0 and Eagle 6.0 2011 pistols (not to be confused with the Desert Eagle pistol) will be offered chambered in .357 SIG.

Sti Eagle 5.0
STI Eagle 5.0

According to the latest STI newsletter, they got a lot of request for this caliber at SHOT Show ’09. I am surprised, I did not know that this round was that popular. The .357 SIG was developed in 1994 to replicate .357 Magnum performance in a rimless case suitable for semi-automatic pistols.

File .357 Sig.Jpg - Wikipedia, The Free Encyclopedia
.357 SIG cartridge.

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • I think I questioned this caliber here. Considering replacing my revolver with a sig.

  • The .357 SIG was developed in 1994 to replicate .357 Magnum performance in a rimless case suitable for semi-automatic pistols.

    You’re exctly right of course, but still I am biting my tongue trying not to say anything about the 10mm… 😉

  • Antagon

    When the slide strips a round of .357 Sig from a mag, all tbhat remains is shoving a 9mm bullet into a 10mm hole.

    Some competition shooters like the because it is expected to run reliably with no fuss.

  • Tom

    I haven’t bitten on .357 SIG myself, mostly because it’s so expensive. I don’t know if it’s just the local shops raising prices due to low demand here or it’s genuinely pricey.

    I suppose I’m just too pragmatic to buy a carry gun in a caliber I can’t forage for in case of emergency 🙂 If it really gets popular I’d like to buy one just for variety’s sake though, hah.

  • 22lr

    I never got the point of making a semi cartridge that replicates a wheel gun. We all now that no 1911 is going to be able to match a real 357, LOL just kidding. I guess people just don’t go for the revolver anymore, O well that leaves more for me.

  • Brandon

    i want sig to make a 10mm conversion for my p250, oh wait this was about 357sig…why can’t these people use what is already available instead of constantly reinventing the wheel? the 10mm already existed, and is more powerful than a 357 magnum. sig should simply have chambered their guns for the 10mm.

    even in a subcompact the 10mm is better. glock has put 10 rounds in their 29, same as their 9mm subcompacts

  • I’m up to four .357 Sig pistols and it’s become my favorite caliber, eclipsing 10mm, only two there, G29 and G20. My “Sigs” are a P226 Sig Sig, Steyr M357-A1 and two S&W M&Ps in .357 Sig, the so-called full-size (4.25″ barrel and really a compact) and what S&W calls the compact (3.5″ barrel and called subcompact by all other makers). Great shooters all and great carry.

    As for high ammo costs, two words. Georgia Arms. Picked up $1K of range ammo, Speer Cleanfire Frangible, for only $200. It’s gone up since, but still cheaper than FMJs and shootable at indoor ranges that ban FMJs.

  • Overload in CO

    As a necked cartridge, wouldn’t this make reloading more complicated as you’d need to lube (and wipe) your cases?

  • Al

    IPSC may have something to do with .357sig popularity. IPSC has allowed this cartridge as the only 9mm/.38 cal for standard major division. (Previously had to be minimum .40cal).

    Countries like Australia prohibit pistol cals bigger than 9mm/.38 for the general safety of muppits. So far Australians have to custom build to shoot standard major, so a decent off-the-shelf pistol in this cartridge will be very popular.

    • Al, I didn’t think of that.

  • Mat

    A lot of highway patrol departments use .357 SiG. Texas, North Carolina, and Virginia come to mind.

    I read somewhere that tests were done firing common autopistol rounds though windshield glass and the .357 SiG was the only one that would penetrate the glass without deviation. Very useful for highway patrol encounters with perps trying to run them down.

    Bottleneck rounds feed smoother. I have never had a stovepipe out of hundreds of rounds fired through my .357 SiG P226. My .45ACP P220 will stovepipe on me occasionally, as will my 9mm CZ.

    And lastly, it is very accurate.

    I think it would make an excellent carbine/submachinegun round. If Beretta would make a CX-4 Storm in .357 SiG I’d be on it like white on rice.

  • MIKE

    I agree with Brandon we keep seeing these new calibers coming out and they keep saying how much better in power these new calibers are. If they would just look at the 10mm again its already been done and the 10mm has the power they keep trying to get. With today’s carbon fibers and powders it would cost less for the major gun companies to come up with a new 10mm handgun and then have the major bullet companies bring back the full power 10mm ammo.
    With today’s new powders they could bring back the full power 10mm round with less recoil and less pressure and that is what everyone that was complaining about the first time with the 10mm. If they did that they would not only have a winner the sales on this gun would go through the roof. And this time they need to make sure to advertise better that is what they forgot to do the first time which was good advertising. Not many people even know that there is another new 10mm why bad advertising.

  • G’day,
    In Australia we now have all the gutless muppets trying to ban semi-auto pistols completely, which is a total joke because 85% of murders here are done with knives. What are they gunna do next, ban us from having kitchen knives or are they just going to restict us to 2 inch blades?

    I have been working through the process of buying an STI from the N.S.W Distributor at Auburn Shooting Academy, Dave Crittendon. STI. So many brilliant pistols, so hard to choose, those Texans sure do know how to make a precision 1911 mate !

    I had it parred down to either The Tactical 5.0 , The Edge or The Eagle 6.0 chambered for .38 super with a 9 round clip because until 5 minutes ago I thought that was as good as it gets Down Under, but now … You Little Ripper ! The EAGLE 6.0″ in .357 SIG ! That’s the ducks nuts !!! Yee Haa! Time to max out the credit card !
    Cheers Mate.


    i have this eagle very high quality and price i expensive

  • Wally

    Ammu, how is the double tapping with your Eagle 357Sig? How do you do with the reloading process of your ammo?

  • Al

    Wally, Do a search at IPSC Global Village, or IPSC Australia Forum. Here we have to make the .357Sig work for local reasons. It must work 100% for sportin reasons. Heavy projectiles (around 160gn) and slow pistol powder delivers 100% sportin reliability an pf’ormance.

  • Wally

    Thanks Al, am waiting for the Forum registration approval. And will check them ASAP. This would help me decide if I would change to 357SIG. Presently am competing with 40SW (Standard Div). Thanks again.

  • Fenixom1911

    Hi Guys

    How work this model STI EAGLE 5.0 in caliber 9mm and 45ACP ???
    What magazines cartridges are 9mm and 45ACP max ???
    Whether he is cutting himself 9mm and 45ACP ???
    Like with the durability of material STI ???
    PLZ OPINION :))))

    Regards Fenix

  • Fenixom1911

    How work caliber 9mm and 45ACP ?????

  • Kevin Wicks

    G’day Chaps

    The talk of a factory STI is of interest. As you are aware we IPSC shooters in Aus are restricted to a max caliber of .38. A fair few have either rechambered their .38 supers or rebarrelled in 357, bought new mags, dies & were away. I noticed that the 357 Sig STI pistol is an Eagle. I run an STI Edge & I like the “wide” frame, so the question, do they make the Edge in 357 ?

  • Fenixom1911

    Hi Guys

    How work this model STI EAGLE 5.0 in caliber 9mm and 45ACP ???
    What magazines cartridges are 9mm and 45ACP max ???
    Whether he is cutting himself 9mm and 45ACP ???
    Like with the durability of material STI ???


  • Al

    The .357 Sig is a .40 case necked down to 9mm. It’s not a new idea, look up when it was developed.

    Any .40 cal semi-auto can be converted to .357Sig with just a new barrel. Everything remains .40 cal except the bore, projectile, and reloading dies.

    What do you get from a .357Sig? With 125gn projectiles…hyper velocity and nice muzzle flash! With 165gn projectiles…around 1100ft/sec and uber penetration.

    Unfortunately the .357Sig cartridge cannot take much more than a 165gn projectile because the OA length must be similar to a .40Cal. The.40cal can take a heavier projectile because of diameter, and a .45 even more so.

    If I could choose between a .45 and a .357Sig it would be a .45…huge stopping power in a very relaxed cartridge! The .357Sig is more stressed like a .40, and it copes no problem but there’s more stress.

    My .357Magnum revolver could not make Major Power Factor in IPSC without exceeding the recommended loading data. My .357Sig semi-auto makes Major well within the loading specs, but nothing like a .45.

    Magazine capacity is another factor. Look at Para double-stack mags… 9mm=18. .40 and .357Sig=16. .45=14.

    So many choices; so hard to choose!

  • Al

    STI and a SVI? They are both top-of-the-range 🙂

    SVI has more options and more polish, but there’s little difference when looking at the target.