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What's the Big Deal with the .357 SIG?

Discussion in 'Caliber Corner' started by Dave Nowlin, Feb 26, 2013.

  1. Dave Nowlin

    Dave Nowlin Fisher of Men

    Dec 20, 2011
    Savannah, Tn.
    The Glock pistol was designed to handle the 9mm NATO round from day one. The pressure spec for the 9mm NATO goes as high as 42,00 p.s.i. When shooting that kind of 9mm loading, what advantage does the .357 SIG really offer if any?
  2. Two Guns

    Two Guns VIP MEMBER

    Nov 4, 2004
    It offers alot more speed.

  3. And speed equals more hydrostatic shock, a bigger permanent wound cavity and a much bigger temporary wound cavity.
  4. barth

    barth six barrels

    Oct 7, 2011
    The Free Zone
    A lot depends on bullet design.
    But 357 Sig has a great reputation for light barrier penetration.

    Plus it closely approximates 357 Magnum performance in a semi-auto.
    And that sort of speaks for itself.
    Last edited: Feb 26, 2013
  5. Dave Nowlin

    Dave Nowlin Fisher of Men

    Dec 20, 2011
    Savannah, Tn.
    Do a little research and find out what the 42,00 p.s.i. NATO loading in 9mm can do. Of course without FMJ bullets. With 115 grain hollowpoints I suspect it can do anything the .357 SIG can do.
  6. dbarn


    Dec 16, 2011
    Per Speer, and I quote:

    The 9mm is a 35,000 psi, +P is 38,500 psi and +P+ is 40,000 psi. The 357 SIG is a 40,000 psi. Bullets of the same weight will approximate the same velocities in SIG and +P+. The difference is gun construction, all 9mm's will not handle +P+. All of the 357 SIG's are made to handle the pressures for the caliber.
    Shoot Straight!
    Coy Getman
    CCI/SPEER Technical Service
    2299 Snake River Ave.
    Lewiston, ID 83501
    (800) 627-3640 ext. #5351 (pound key must be used)

    Personally, if I'm going to shoot 40,000 psi, I want a pistol designed and constructed to start at 40,000 psi.
  7. Dave Nowlin

    Dave Nowlin Fisher of Men

    Dec 20, 2011
    Savannah, Tn.
    dbarn, I am in complete agreement with you. My research however leads me to believe that the 9mm Glock was designed to handle that type of pressure. Study the barrels and you will discover that the walls surrounding the chamber in a 9mm Glock are thicker than those for the .357 SIG. The external dimesions are the same but the .357 SIG is a necked down .40 S&W. This leads to thinner walls in the chamber area. The barrel area is identical. Same external dimension and same bore. Am I missing something here that logic doesn't reveal?
  8. dbarn


    Dec 16, 2011
    The .357 sig barrel has a fully supported chamber. Additionally the slide is heavier. It would be interesting to see what Glock had to say about a steady diet of +P+ in their 9mm designed pistols.
  9. humphreys19


    Feb 4, 2011
    No dog in this fight, but for me, if you want more than 9mm +p+.... go to 10mm. my G29 is primo.
  10. Dave Nowlin

    Dave Nowlin Fisher of Men

    Dec 20, 2011
    Savannah, Tn.
    All I can say is I bought my first Glock in 93 or 94 and in that time frame I talked with one of the Glock Techs working that at that time who told me that the 9mm Glock pistol would chamber and fire 9mm sub gun rounds with no adverse effects. Was he telling me the truth? I don't know and the product liability lawyers wouldn't allow a Glock employee to say that today, even if it is true
  11. TomAiello


    Jan 8, 2012
    Twin Falls, ID
    How many people can afford a steady diet of +P+ for their 9mm glocks? And how many manufacturers make a +P+ range ammo? Any?

    I'd expect to see the +P+ as carry ammo, with the standard pressure used for training purposes.
  12. Dawolf


    Sep 18, 2010
  13. JoeTho


    Feb 7, 2013
    I dig the sig! I converted my Glock 27 into a 357 sig. Based on everything I read the sig cartridge is like the 9mm +p+ on steroids. Some claim the difference between the 9mm +p+ and the 357 sig is only marginal, but that's a difference I will take.

    Posted using Outdoor Hub Campfire
  14. iflyem1

    iflyem1 Member

    Mar 15, 2009
    I never shot the 357 sig but I'm very intrigued to say the least.
  15. G26S239

    G26S239 NRA Patron

    Mar 17, 2008
    3 of my 7 40s are also 357. I prefer going with the greater bullet diameter of the 40.

    There is a .2 ounce difference in slide weight between a G27 and a G26. The difference is .4 ounce between G32 and G19. The Glock Armorers Manual okays the use of +P+. My 1999 G26 has over 1000 rounds of Winchester and Remington 115 grain and 127 grain +P+ through it. HK USPs are specifically okayed for use of +P+ and my Beretta 92FS and Nano manuals allude to use of +P+ without forbidding it.

    So far none of my Glocks, Sigs, HKs, Berettas or CZ that I have put +P+ through have suffered catastrophic failure or undue wear.

    I don't see how using 40k psi ammo with a power factor of 175 through an 11.8 ounce (with factory plastic sights) G27/33 slide is safer than shooting 40k psi ammo with pf of 157 through an 11.6 ounce (with factory plastic sights) G26 slide.

    And as Dave Nowlin mentioned my G19 barrel has thicker chamber walls than my G32 barrel.
    Last edited: Feb 26, 2013
  16. one thing that was brought up in a previous thread on the subject was that the breachface thickness is thicker on the .40 and 357sig compared to the 9mm.
  17. PghJim


    Apr 21, 2005
    A 9mm +p+ is undefined; it is generally 40,000psi - 42,000psi. The 357 sig is defined at 40,000psi. In a 4.5 inched barreled G32 the current Underwood 357 sig goes 1,550fps. The hottest +p+ 124gr 9mm goes 1,330fps out of the same barrel length. At full potential the 357 sig offers significantly greater velocity and energy than a 9mm +p+. Street performance for the 357 sig has been exellent and similar to the 125gr SJHP of the 357 magnum. People should really try out the sig, it may be more expensive but I feel it is a great cartridge and my every day carry gun.
  18. unit1069


    Oct 10, 2007
    So. Central US
    What this comparison comes down to, performance-wise regarding pressure, is that the 9mm +P+ is pushing the 9mm limit whereas .357sig isn't even breathing hard at the same level. I've read that .357sig could be loaded to greater pressure, but in my mind that would be far less worthwhile than developing new bullet choices, which are relatively few compared to what's available with 9mm.

    I think its the bullet design that clearly gives the .357sig the edge. There are many excellent 9mm JHP self-defense rounds but the older, lighter 9mm bullets pushed to extremes don't expand as well as the newer, slower, heavier designs and penetrate on average less than the heavier bullets. And the heavier 9mm rounds --- as good as they are --- don't perform nearly as well when pushed to +P+ limits.

    The .357sig JHP bullets (with the bulge, not the 9mm bullets some companies use in their .357sig rounds) seem to be just about right for self-defense purposes, with the added advantage of impact event results that sometimes appear explosive in the first 6-8 inches of calibrated gel. Nobody has proved it yet, but reading articles that quote LEO who have seen real world .357sig results it does anecdotally compare favorably to the 125-grain .357 Magnum.

    I own both 9mm and .357sig and believe either one will get the job done. I just also happen to believe .357sig has greater applications given its greater power and range. Just as I wouldn't try to make my 9mm into a clone of a more powerful caliber neither would I want to attempt to defeat the .357sig's design by trying to push its limits.

    I do own some 115-grain Federal 9BPLE and have confidence in it, but I find myself carrying a few 124-grain premium JHP rounds more often than the 9BPLE. High pressure/high velocity may mimic a more powerful caliber but to me if it falls short of the performance I can get with a standard or +P round then it's a self-defeating proposition in trying to wring out the last fps possible in a given caliber.
  19. plouffedaddy


    Apr 1, 2011
    The big deal is it is easily capable of being loaded to 357mag specs but in a package that holds 15+1

    [ame=""]Underwood Ammo 357 SIG 125gr Gold Dot JHP Ballistics Gel Test (HD) - YouTube[/ame]
  20. Dave Nowlin

    Dave Nowlin Fisher of Men

    Dec 20, 2011
    Savannah, Tn.
    I'm having a hard time swallowing some of the rationale used in defending the .357 SIG. The 9mm +P+ is breathing hard but the .357 SIG isn't breathing hard at the same pressure level. An interesting observation. 40,000 p.s.i. is 40,000 p.s.i. regardless of caliber. Is the brass in the .357 SIG thicker than in the 9mm? I don't know. It has already been observed and testified to that the chamber walls are thicker in the 9mm. If trying to contain pressure would you prefer super strong brass and strong chamber walls or strong brass and super strong chamber walls. I will personally go for the super strong chamber walls. The strongest brass out there won't contain the pressure if the chamber walls which support it fail.

    Now that that issue has been covered there is the issue of flatter shooting at long range. For those of us who are citizens and not LEOs, you'll have a hard time defending the concept that a long range shooting was self defense. A man much smarter than me once said, "a hand gun is to be used to get yourself to your long gun." A handgun is a short range self defense weapon at best. My AR would be a far better choice at distance. Why do you suppose so many departments are buying into the Patrol Rifle concept?

    If there is a true advantage to the .357 SIG then it would come from greater case capacity. If the proper powder was chosen to be optimized to the barrel length of the gun maybe there would be some small advantage. By optimized I mean the burn rate would be chosen to produce the the greatest amount of energy within the chosen barrel length without exceeding the pressure limit. This means that the ammunition companies would have to optimize their ammo to barrel length. Fat chance of that.

    In the 26 & 33 considering their short barrel length the difference in energy produced would be minimal at best. Dead is dead and overkill is overkill. At practical and justifiable self defense ranges the out come between the two calibers inside 10 yards really would be hard to predict. In a real shooting the metabolism of the victim and other factors would create a much harder to predict outcome than these two caliber choices.

    This is like trying to predict which is better for deer hunting, a .270., 7mm-08, .308, 30-06, 7 mag or whatever to kill a deer. Any of these calibers is more than adequate. It's truly a matter of personal choice. While choosing you better consider the little thing called overpenetration. We are after all responsible for any and all damage that bullet does after it leaves the muzzle.