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If Penetration is King, Why 125 gr .357?

Discussion in 'Caliber Corner' started by BroknPrism, Jan 23, 2012.

  1. BroknPrism


    Feb 28, 2005
    I keep hearing that the heaviest bullet in a given caliber is the right move, because penetration is 'better' than expansion. So why has the .357 mag reigned for so many years, and why does the .357 Sig follow the 125 gr tradition?

    Is it because, for most of the 357's reign, it had hardball 9mm and .45, and RNL .38 special as its competition...? But if that's true, why a 125 gr .357 Sig? Why not a 158 gr bullet? Too long for the case?
  2. Because overpenetration is a bad thing as well. The 125 grain bullet in 357 sig is made "tougher" to withstand the velocity. Too heavy of a round tends to pencil through without "opening" unless it hits something solid. Too light and it won't penetrate to the vitals like a parachute opening that slows it dramatically when expansion occurs. The 357 mag and Sig tend to move light bullets fast, hence the phrase speed kills. A 158 grain bullet would most likely not work in the Sig since it would use too much case capacity for where the powder would need to be and it would be seated to long to fit in a magazine. Other than that I really can't give you any better explanation.

  3. Andy W

    Andy W

    Dec 4, 2006
    Because the penetration is everything line of thought is BS. Sure, we want a bullet that penetrates deep enough to reach vital organs but we also don't want a bullet that is specifically designed to punch through 18 inches of meat and only flatten out at the tip, leaving a very deep but narrow wound channel. What sounds more damaging assuming they hit in the same place, a clean pass through wound the size of a woode dowel, or a nastly jagged wound the size of a silver dollar with the bullet lodged under the skin on the far side of the body?
  4. DocKWL


    May 15, 2009
    I posted this in another thread yesterday and out of simplicity will copy the information here. You would do well to read the other two myths contained in the link:

    Myth Number 2: The Fackler-IWBA Stopping Power Theory is "Deep Penetration"

    This classic piece of disinformation has been promoted by gunwriters Ed Sanow and Massad Ayoob since the early 1990’s. Sanow and Ayoob frequently paraphrase: "According to Fackler-IWBA, if penetration is everything, the 9mm FMJ cartridge should be one of the most effective loads on the street."
    Sanow, Ayoob and other gun-writers who make this assertion are either uninformed or dishonest.
    The Fackler-IWBA concept of rapid incapacitation is about DISRUPTING VITALS.
    According to Fackler-IWBA, rapid incapacitation is a function of damaging or destroying tissues that are critical to an attacker’s immediate survival. Consequently, the bullet must pass through vital structures to be effective. If the bullet does not pass though major blood distribution organs or the central nervous system, it will not dependably force an attacker to quickly collapse.
    To reliably accomplish this task, the bullet should be capable of penetrating deeply enough to reach and pass through vital structures in the body from any angular aspect. This capability is called adequate penetration.
    Fackler-IWBA recommend a minimum of 12-inches of penetration. This 12-inch minimum penetration performance guideline is meant to ensure that the bullet has adequate penetration potential to reach and disrupt vitals. That’s it!
    The 12-inch minimum penetration performance guideline ensures the bullet has sufficient penetration potential to reach and pass through vitals; not only when penetration conditions are favorable, but unfavorable as well, such as when a bullet has to perforate arm muscle and bone before it enters the upper torso.
    An arm obstructs about 20 percent of the torso when it is outstretched and pointing a gun, and you're shooting at the bad guy from a front angle. Likewise an arm can obstruct 50 percent or more of the torso when you engage a bad guy with gunfire from a side angle. Therefore there’s a good chance that your bullet could hit an arm, and that’s part of the rationale behind the 12-inch minimum penetration performance guideline.
    (Pre-fragmented bullets like MagSafe and Glaser are easily defeated by an arm, and this is why we feel they're inadequate for personal defense use. Any pellets that manage to exit the arm and penetrate the torso are going to produce minimal wounding effect. Pre-fragmented bullets require best case conditions to produce maximum wounding effect.)
    The minimum penetration depth guideline recognizes that combat is chaotic, and it is meant to eliminate tactical uncertainty that a well placed shot will be defeated by common obstacles such as an arm or an unusual shooting angle that requires the bullet to negotiate several inches of non-vital tissues to reach and damage vitals. 12 inches of penetration provide a margin of safety in situations such as these.
    Penetration doesn’t mean a thing unless vitals are damaged and destroyed. A deep penetrating bullet that plows past vital structures without going through them is just as ineffective as a shallow penetrating bullet that stops an inch short of the heart.
    The intent is to optimize a bullet’s wounding efficiency by striking a balance between adequate penetration and reliable expansion.
    Let’s examine Ayoob’s and Sanow’s absurd assertion about the effectiveness of 9mm FMJ ammunition: A 9mm FMJ bullet, with its smooth, semi-pointed, streamlined shape is less efficient in crushing tissue than an expanded hollowpoint bullet. A round nose FMJ bullet crushes a permanent cavity in soft tissue that averages approximately 66 percent of the bullet’s diameter.1 Whereas the blunt, non-aerodynamic shape of an expanded JHP bullet crushes a permanent cavity that averages approximately 82 percent of the bullet’s expanded diameter.1 A 9mm FMJ bullet that penetrates the heart is not going to produce as effective a wound as a 9mm JHP bullet which has expanded to .60 caliber that penetrates the heart. The rate of blood loss through the hole produced by the FMJ is not going to be as fast as the hole produced by the expanded JHP. Therefore the FMJ bullet's wounding efficiency is inferior to the JHP bullet.
    The Fackler-IWBA concept is not "deep penetration." Penetration is a terminal performance characteristic that does not determine "effectiveness."

    The Fackler-IWBA concept is disrupting vitals to produce rapid and reliable incapacitation.

    End Notes:

    1. MacPherson, Duncan: "Table 8-3: Projectile Penetration Model Parameters, ø (Bullet Shape Factor)," Bullet Penetration, Ballistic Publications, El Segundo, California, 1994; pp. 205.

    I am a staunch supporter of the physics behind heavy-for-caliber bullets and can attest to the destructive power of a 200 grain 10mm at 1200 fps, but to recommend carte blanche that combination based strictly on it's aptitude for penetration alone would be absurd.

    I will let others answer the remainder of your questions. At this time, that is thin ice I care not to walk on in this forum.
  5. English


    Dec 24, 2005
    The .357 Magnum had quite a long reign as the most effective hangun cartridge. During that time the most effective loads went from 158gn to 125gn. This was a matter of accumulated experience rather than any scientific study, but was the basis for the design of the 357SIG with 357 Magnum performance from a 4" barrel pistol of 9mm dimensions and relative to a 4" barrel .357 Magnum.

    What finished the .357 Magnum era was the fact that LEOs were getting into more and more gunfights against criminals with high capacity 9mms. Magazine count is easy to measure and terminal ballistic effectiveness is not, so since high capacity 9mms were available at that time and 357SIGS were not there was a major switch to 9mms by agencies.

    Contemporaneously with this there was a move towards a perceived need for more penetration for the reasons outlined in DocKWL's post above which is more rational than most expositions of that position but is full of internal contradiction.

    The first problem with that viepoint is the stress on hitting "vitals", and when you look at that alittle more closely you see that the reason for that is to increase the rate of blood loss. As a mechanism for killing someone, sufficient blood loss is certain, but as a means of incapacitating someone it is far too slow. The FBI has claimed that a fit determined man can continue to fight at a lethal level for 15 to 30 seconds after his heart has been shot out rather than just penetrated. Some claim that the FBI says only 10 to 15 seconds, but if you consider that it is easy to fire at a rate of 4 shots per second that still gives him time to fire 15 shots, reload and fire some more. Rather than self defence this is a strategy of mutual suicide.

    DocKWL points out the obvious fact that many on the same side do not seem to understand. Penetration alone is not enough. We cannot rely on our ability to place our shots precisely when at close range under fire and so we need to do damage to a wider zone around the bullet track than the width of the bullet. And so we need expanding bullets. DocKWL thinks of this as nearly doubling the diameter and that means that the volume of tissue damaged is about three times as great. What it also means is that the penetration is reduced because the hydrodynamic drag is increased. What that also means is that the bullet is transmitting energy to the tissue at a much higher rate and that damages tissue beyond the width of the bullet, but DocKWL does not want to talk about that and does not believe it to be so.

    Penetration is undoubtedly essential but we have to choose a compromise between penetration and width of the zone of damage. Undoubtedly an arm, the gun arm in particular, is likely to be hit in about 20% of shots before the bullet reaches the body. The obvious conclusion is that we need enough penetration left still to reach the "vitals". There are two things wrong with this conclusion, if not three! The most obvious is that if we hit the gun arm well enough to affect penetration of the body, the BG will be unable to use that arm and hand to shoot at us and so we can make more hits before he can adapt and use his other arm after perhaps picking his pistol off the floor. The second is that it is only a 20% chance and so we must weigh that against what we loose by biasing the compromise towards penetration rather than a wider zone of damage. This is all a matter of averages and there is no guarantee which average you will get. On top of that we expect to fire multiple shots and train to do so. Hitting an arm with one of them will not make a huge difference to the outcome and, if anything, will be a benefit rather than otherwise because of the disruption caused to his ability to shoot at you.

    In this conclusion that a load is needed which will reach the "vitals" after hitting an arm, no allowance seems ever to have been made for reality. That is, it is a reasoned conclusion that has not been tested by data. The data is not really there because it is hard to collect and classify, and so we are thrown back on theory and anecdote. The anecdotal evidence for the 125gn .357 Magnum is strong and so seems to be the evidence for the 357SIG. In other words the belief that heavy for caliber is best seems to be unfounded.

    .357 Magnums in particular seem to have produce a significant proportion of "one shot stops" where the individual collapsed totally incapacitated after a singel hit. The same seems to be true of the 357SIG. This is a serious problem for the people who claim that the only two routes to incapacitation are loss of blood pressure and direct hits to the CNS because most of these cases did not hit the CNS and collapse came in far less time that bleed out or blood supply failure could achieve. What ever is causing this effect it does not fit the Fackler model to which DocKWL subscribes.

    You are obviously new here and so it is worth saying that these issues produce quite violent emotional responses from the Facklerites but no evidence and little attempt at explanation. In fact DocKWL's post above is probably the most I have seen in way of reasoned support for the Fackler position. If you read a little into the subject you will find various pseudo explanations from Fackler and his followers for rapid collapse. I probably can't recall all of them at the moment, but distortion of the time sense, and a desire for attention by LEOs involved in shootings. A BG knowing from films that he is supposed to die when shot or just giving in from pain or fear are others.

    You will get several people claiming long significant experience of shooting people and attending autopsies who will insist that they know best and should not be questioned putting pressure on you for asking your question. For them, there is no argument.

  6. Merkavaboy

    Merkavaboy Code-7A KUZ769

    Well said English.

    I must state that reading posts by some people who are very militant about this topic reminds me of a movie line: "It is the wool that has been pulled over the people's eyes".

    What happens inside a labratory is not the reality of what happens out on the streets.

    One can control nearly every aspect of a test inside a labratory, but one cannot control the dynamics of an actual gunfight.

    It all boils down to what you, as an individual, wishes to believe in; which side of the field you choose to sit on.
    Last edited: Jan 23, 2012
  7. Four Knives

    Four Knives

    Dec 25, 2009
    +1 @ English

    However OP:

    "Shot PLACEMENT is king, penetration is Queen...everything else is angels dancing on the heads of pins"
  8. DocKWL


    May 15, 2009
  9. unit1069


    Oct 10, 2007
    So. Central US
    I don't recall ever reading Marshall & Sanow or Ayoob stating such a thing. Do you have a link to actual texts these men have written or is what you posted (apparently so) someone at fashioning a strawman argument?

    A little clarity on this point, please.
  10. pisc1024

    pisc1024 AASG

    Oct 9, 2005
    Hey, if you want a good discussion on terminal ballistics you should go to and check out the terminal ballistics forum. The discussions here in GT are nothing short of ridiculous. There are a lot of "occupy caliber corner" protesters here who like to produce a white noise that has nothing to do with the discussion. I might add most of these people have no idea what they are talking about.
  11. jeffreybehr

    jeffreybehr Silver Member

    Mar 14, 2009
    Phoenix, AZ USA
    Interesting. Fortunately I've never had to even expose my carrygun, much less shoot it, to protect mine or others' lives.

    I believe that shot placement is indeed MOST important. After that comes penetration WITH good expansion so that the bullet delivers all its energy into the body of the BG. Bullets that come apart may cause some incidental damage, but a 2- (or 5- or whatever-) grain fragment of jacket will not do much damage to the BG. I use the highest-quality bullets I can find in the medium weights for the 2 calibers I shoot, test them for expansion AND weight- and shape-retention, and make sure they function absolutely perfectly in my guns. I practice shooting, too, altho not as much as I should.

    I just can't get into the technicalities of these issues.


    I use the 125g. Barnes all-copper TAC-XPs (at c. 1360FPS @ 10') in my 357SIGs and the 155g. Federal HST (at c. 1380fPS @ 10') in my 10mm. Both bullets expand beautifully AND retain all weight in my waterjug tests.

    The TAC-XP 125s.

    The HST 155s.

    And yes, I know that waterjugs do NOT present the same difficulties to the path of bullets as do human bodies, but a series of 1-gallon waterjugs with the 1st's front covered with 8 layers of denim is repeatable and easy to do, whereas I don't happen to have any human bodies to shoot...fortunately. And bullets that come apart in waterjug testing are NOT those that I use for personal defense.
  12. smokeross

    smokeross GTDS Member #49

    May 15, 2011
    I prefer my .44 magnum with 265 grain Horandys pumped up to maximum velocity. But of course, I am more concerned with Brown Bears than thugs. 12 inches of penetration won't do much to a Brown Bear. The last one I killed was 9 1/2 feet nose to tail. I shot him 7 times with a Winchester model 71 with 250 grain slugs. There were no exit wounds. Oh, and the model 71 holds 5 rounds, so I had to do a quick reload at 25 paces. That'll get your blood pumping.
  13. dkf


    Aug 6, 2010
    The .357sig and .357mag 125gr loads work and have been proven to work. Good enough for me. Once I get a chrono I'm going to experiment with some hot 147gr .357sig loads. Worse case I end up with a 9mm 147gr bullet that goes 100+ fps faster than a 147gr 9mm load.
  14. 9mm +p+

    9mm +p+

    Mar 1, 2005
    Old Dominion
    I started in LE in the early 90's as a reservist, I was issued a 4" 686 with fed 125's as was everyone else at the time. I've seen the 357/125 used firsthand as well as several others over the years. NOTHING that I've seen short of a 12 ga. slug is as rapidly incapacitating of a human being as the 357/125. Sure it old fashioned and doesn't have some cool acronym attached to it, but it works very well even today. All of my 357's are loaded with it as I type this. Penetration? The firstshooting that I was personally involved in was a very large suspect in the neighborhood of 375lbs, 1 shot which was a through and through shot stopped him in his tracks. Machete hit the ground and so did said bad guy, dead before he hit. Exit hole in the center of his back was fist sized, bullet had fragmented some but still had enough oooomph to break out his trucks side window and was found on the passenger side of truck seat. There are lot's of rounds that are close but none that are better, the proof is in the performance,period.
  15. cowboy1964


    Sep 4, 2009
    I read everything Ayoob puts out and I don't recall him advocating FMJ for any caliber, least of all 9mm. Quite the opposite in fact. There is an 20 year old video of him on YouTube where he is talking about the idiocy of FMJ.

    [ame=""]Massad Ayoob - Shoot To Live - 4/8 - YouTube[/ame]

    "Nothing is everything and everything is something." Penetration isn't important, ideal penetration is.
    Last edited: Jan 23, 2012
  16. Rumbler_G20


    Dec 5, 2011
    N. Florida

    Amen! VERY well said. :cheerleader:
  17. fredj338


    Dec 22, 2004
    I actually don't buy completely into "penetration is king". If that were all there was to it, then we would all still be using FMJ. It's a balance of penetration & tissue destruction. You want both ideally. A good 125gr 357mag will do that, a poor design will not.
  18. Tiro Fijo

    Tiro Fijo

    May 31, 2011

  19. BroknPrism


    Feb 28, 2005
    Thanks for the informative replies. I wasn't advocating a position, just tossing it out for discussion. I normally carry the heaviest bullets in any caliber, but would (still) carry 125s in a .357 if I had one. There must be something unique about that combination of velocity and expansion. It's FM. If I buy a .357 Sig conversion barrel for my 22, I'll go with 125 gr.