JHP vs FMJ for Defense.

[Madcap_Magician]

Even a fully expanded bullet does not provide a magically larger wound that will incapacitate in a meaningfully faster period.

That being said, at least with JHP ammo there is a chance that the round will expand, a chance that the expanded round will hit something that an FMJ round would have missed.

Slim chance of additional effectiveness and slightly reduced chance of overpenetration is still worthwhile, all else being equal.

YMMV.

 

[481]

Even a fully expanded bullet does not provide a magically larger wound that will incapacitate in a meaningfully faster period.

That being said, at least with JHP ammo there is a chance that the round will expand, a chance that the expanded round will hit something that an FMJ round would have missed.

Slim chance of additional effectiveness and slightly reduced chance of overpenetration is still worthwhile, all else being equal.

YMMV.

MM-

Well said.

I agree. I doubt that there are many who could or would notice a difference between an FMJ or JHP as it zipped through their vitals.

Still, no matter how small the "advantage" might be, I'll take the JHP over an FMJ anyday of the week since I want to avail myself of every possible benefit that there may be, no matter how small it may be.

Since I've been trained over the course of my career to shoot until the threat is resolved as opposed to firing just one shot and "pinning my hopes and dreams" upon its performance, debate such as this is simply "much adieu over nothing" IMNSHO.

 

[Manco]

Still, no matter how small the "advantage" might be, I'll take the JHP over an FMJ anyday of the week since I want to avail myself of every possible benefit that there may be, no matter how small it may be.

For what it's worth, based on my earlier rough quantification of bullet effectiveness based on diameter, I would say that using JHP would give you at least a 10% improvement (and probably 20% or greater in the real world) in the probability of hitting a typical vital area over FMJ, per bullet, all else being equal (this is a conservative lower bound based on other factors not considered). Additionally, this is a much larger improvement than you would get by using a larger caliber than 9mm (with FMJ bullets), assuming adequate penetration in all cases. This is simply the result of the relative dimensional scales of bullet types, their diameters, and vital organs.

So for those who choose to carry FMJ ammo to save money, for example, in my opinion it most likely would not be worthwhile to use .45 ACP because it does not significantly outperform 9mm with FMJ rounds and 9mm generally costs less (and allows for higher capacity). For others, the best thing to do would be to shoot less expensive rounds of the largest caliber you're comfortable with, practice often enough to become proficient, and load self-defense handguns with JHP rounds for maximum effect.

 

[481]

For what it's worth, based on my earlier rough quantification of bullet effectiveness based on diameter, I would say that using JHP would give you at least a 10% improvement (and probably 20% or greater in the real world) in the probability of hitting a typical vital area over FMJ, per bullet,...

While your post was an interesting mathematical exercise, the only way to establish its validity would be to evaluate it against real world results. The problem with such exercises is that they tend also to be only of heuristic value, an exercise in "what if" as it were.

...all else being equal...

The problem with this is that more often than not, "all else" isn't.

So for those who choose to carry FMJ ammo to save money, for example, in my opinion it most likely would not be worthwhile to use .45 ACP because it does not significantly outperform 9mm with FMJ rounds and 9mm generally costs less (and allows for higher capacity).

Though the 9mm "haters" won't like it, this is most likely true.

For others, the best thing to do would be to shoot less expensive rounds of the largest caliber you're comfortable with, practice often enough to become proficient, and load self-defense handguns with JHP rounds for maximum effect.

Good advice.

 

[solvability]

My .02 - it has to cut something important to stop the attack fast. From a frontal shot the JHP should increase your chances because of surface area (if no other factor) but from a side shot or through a shoulder or major bone the FMJ has a better chance of transiting a critical structure. I use JHPs and truncated cones which do give more cutting action than round nose and they tend to transit tissue in a straighter trajectory.

In a 380 or Mak - I only use FMJ - no other way to assure enough penetration.

 

[mordechaianiliewicz]

I use JHP 124 grains in my Glock 17 because it has the ability to make use of enough of the burning powder for it to gain sufficient velocity to reliably get enough penetration to cause damage to internal bodily structures. In my Kel Tec PF9 (which has a pitifully small barrel), I use FMJ because I want to get enough penetration to make up for the loss in power from the shorter barrel.

I think this rough math is what everyone ought to go with.

But that is just me. Overall, as long as you have enough barrel length, it is always best to use a JHP.

 

[hinton03]

"From a frontal shot the JHP should increase your chances because of surface area (if no other factor) but from a side shot or through a shoulder or major bone the FMJ has a better chance of transiting a critical structure."

Isn't this why the FBI established its evaluation criteria for the selection of a JHP; if the load meets them then it should reach the vitals from all angles.

 

[Manco]

While your post was an interesting mathematical exercise, the only way to establish its validity would be to evaluate it against real world results. The problem with such exercises is that they tend also to be only of heuristic value, an exercise in "what if" as it were.

You're absolutely right, and I've tried to be careful not to overstate the "validity" or concreteness of what basically amounts to a thought experiment. I've proven nothing, really, with regard to calibers and bullet types, although at least somebody finally attempted to explain in numerical terms how certain isolated parameters such as bullet diameter can, in theory, affect the probability of effective wounding.

While I wouldn't put any real faith in the actual numbers generated by such a crude (I could refine it greatly in mathematical terms but that wouldn't make it any more valid), incomplete system of estimation, it at least gives us a sense of scale that can help guide our intuitions as to what type of ammunition we feel comfortable using. And let's face it--at the end of the day, the latter is really all we have regarding this whole subject.

Unfortunately, even the most scientifically rigorous studies have given us few if any answers that common sense couldn't have done, and don't often put a numerical value on the advantages of many parameters, save for minimum penetration. Even then we could make up our own minds, allowing our gut to tell us how much is needed to punch through some bad guy's potentially thick beer gut (many folks think that 12" is good enough, but it's really a bare minimum--the goal should be 18" as the FBI, for one, suggests as being "preferable" meaning advantageous).

The problem with this is that more often than not, "all else" isn't.

True, but I made sure that the most significant, known factors (feel free to bring up any contradicting ones) were on either side of the lower and upper bounds for comparisons. This means that whatever percentage is estimated when comparing JHP against FMJ is a lower bound because JHP bullets have a shape that is superior at wounding, particularly at the edge, while a comparison between two calibers in FMJ is an upper bound regarding round-nose bullets, which wound poorly beyond the tip (additionally, among the most common handgun calibers, smaller tends to be faster).

Though the 9mm "haters" won't like it, this is most likely true.

Honestly, I wouldn't have thought so to start out with, but after taking such a close look at the difference between these calibers and twiddling a few numbers to my own satisfaction, I have to say that the proponents of 9mm use in the military are probably right. I had always had a knee-jerk reflexive response in favor of .45 ACP when forced to use FMJ, but it turns out that it's in all likelihood more advantageous in JHP than in FMJ, which seems to run counter to the "conventional wisdom."

Good advice.

As long as penetration is sufficient, that is. If it isn't, then I'm not even going to touch that comparison, at least for now. Personally, I try to err on the side of penetration because without it there would be a lot of vital tissue out of reach in the lower abdomen, assuming an anterior shot. With FMJ, there is not much question of being able to reach the spine or aorta with such a shot, but JHP may suffer in performance with exceptionally large individuals. This is why I currently use a .40 S&W JHP round that expands like a 9mm but penetrates several inches more deeply, just in case.

 

[spaladino]

Provided equivalent shot placement, what evidence exists suggesting the JHP will stop any faster than the FMJ?

Provided any projectile has sufficient velocity, construction, and/or meets with an object to initiate deformation, it will deform in some way. Due to it's fundamental construction, a JHP will be more likely to deform or "mushroom" than a FMJ, given all the other variables are the same. After this deformation, or lack thereof, in whatever medium, water, phone books, gelatin, tissue, etc., basic friction then takes over. The more "blunted" or non-aerodynamic an object is, the more friction moving through the medium, causing it to lose forward momentum faster.

For me in a defensive situation, if given the opportunity to choose whether I would like to expend all of the energy/tissue disruption that I am capable of delivering in an attacker, or some in the attacker and the rest in the surrounding countryside, I would choose all in the attacker.

To that end, I would want to carry whatever bullet fed 100% reliably in my weapon. In whatever weapon chosen for best fit, portability, capacity, and reliability. With a cartridge that I was confident could deliver sufficient disruption to it's intended target. Fancy labels, exotic or cartridges in blister packs or other nefarious doo-dads... not so much.

As for everything else discussed, bullet placement is paramount to a "successful" defensive situation rather that what kind of bullet. You can't miss fast enough to make a difference in a gun fight.... And I would wager an educated guess that the bad guy with a FMJ or JHP to the eye socket wouldn't know the difference.

 

[481]

You're absolutely right, and I've tried to be careful not to overstate the "validity" or concreteness of what basically amounts to a thought experiment. I've proven nothing, really, with regard to calibers and bullet types, although at least somebody finally attempted to explain in numerical terms how certain isolated parameters such as bullet diameter can, in theory, affect the probability of effective wounding.

While I wouldn't put any real faith in the actual numbers generated by such a crude (I could refine it greatly in mathematical terms but that wouldn't make it any more valid), incomplete system of estimation, it at least gives us a sense of scale that can help guide our intuitions as to what type of ammunition we feel comfortable using. And let's face it--at the end of the day, the latter is really all we have regarding this whole subject.

Unfortunately, even the most scientifically rigorous studies have given us few if any answers that common sense couldn't have done, and don't often put a numerical value on the advantages of many parameters, save for minimum penetration. Even then we could make up our own minds, allowing our gut to tell us how much is needed to punch through some bad guy's potentially thick beer gut (many folks think that 12" is good enough, but it's really a bare minimum--the goal should be 18" as the FBI, for one, suggests as being "preferable" meaning advantageous).

From what you've demonstrated in terms of mathematical capability, I believe that you might get alot out of Duncan MacPherson's book, "Bullet Penetration: Modeling the Dynamics and Incapacitation Resulting from Wound Trauma". MacPherson is a real, honest to goodness, MIT educated "rocket scientist" (he worked on the Mercury program; calculated trajectories and orbital mechanics for the orbital vehicles)

MacPherson's book, if you can find it (it is currently four years out of print), presents much in the way of mathematical penetration models that were derived through actual testing and analysis by MacPherson himself and while the book is "heavy" on the Calculus, it is still "readable" by those with slightly advanced understanding of mathematics although I gather you have more than that.

I believe that you will find quite intriguing the specified drag curves that are printed near the end of the book (on pages 245-255) that allow one to estimate reasonably well (and shockingly so) the penetration of expanding (JHPs) and non-expanding projectiles (FMJs, SWCs, WCs, etc.) in calibrated 10% ordnance gelatin. MacPherson states that his models are accurate to within ~1mm of actual performance and there is a high correlation between his models and reality to be sure.

Although MacPherson does not provide the actual equations that he used to generate these drag curves for his models they can be obtained by non-linear regression analysis (or "advanced fiddling" as I call it) and the process is relatively simple although somewhat time consuming.

Once these equations are (re)defined, it is then possible to determine (within their designed limits) the depth of penetration of any given projectile at velocities ranging from 400 fps to 1600 fps in calibrated 10% ordnance gelatin. It's pretty neat stuff, to be sure.

It is interesting that you mention the FBI's 12 inch penetration requirement as being "a bare minimum". MacPherson addresses the issue in his book stating that setting a "hard" algorithmic requirement of 12 inches is a step in the wrong direction and he suggests that a "soft" algorithm (in essence a preferred range not an immovable threshold) be adopted to qualify what is acceptable and unacceptable bullet penetration.

Even so with this capablility, there are so many more variables that come into play in actual bullet performance in real-life shootings that believing this to be "the answer" is simply an exercise in fallacious thinking.

 

[chemclay]

"To that end, I would want to carry whatever bullet fed 100% reliably in my weapon."

are JHPs and FMJs equally reliable when feeding autoloaders?

when is there a concern about several layers of clothing for us notherners esp. in 9mm?

 

[spaladino]

Unfortunately, all autoloaders are not created equal, and some have trouble reliably feeding some bullet types. My ultra-reliable Sig 226 in 40 S&W does not care for 180gr flatnose bullets. It will eat virtually anything else, but not 180 gr flatnose from a particular manufacturer. Who, by the way, makes outstanding bullets in every other regard. I came upon this fact accidentally. I found a "great bargain" of bulk 40 cal flatnose bullets... not such a great bargain for me, as I soon learned. Only your gun can tell you if it likes a certain type of bullet. Any wide brush of an opinion about your gun and a particular brand or type of bullet is worth just as much as it cost you to hear.... always prove your gun will feed reliably with what you intend to carry.

I'm assuming you're asking about penetration through several layers of clothing, and that is a valid concern. However, I don't believe we can ever truly be prepared for every possible scenario. We can just be as prepared as we possibly can. What if the attacker is behind a barrier, what if he's broadside instead of facing directly, what if the attacker is morbidly obese with multiple layers of clothing, the what if's can go on for quite some time. There is no magic bullet, caliber, or weapon that will dispose of any and all threats we may run across. Which goes back to my original statement - bullet placement is the key ingredient, and the only "magical" component if one actually exists.

There is one real world scenario that we should all take to heart on this matter. Many years ago, there was a infamous gun battle on the streets of California, as I recall. My memory fails me here, but anyone can chime in with the particulars. It was a bank robbery where the bad guys had fully automatic weapons, body armor, etc, that spilled out on the streets. The bad guys eventually lost, and the FBI then declared the 10mm Auto was their preferred cartridge moving forward, because of the lack of penetration/power their various weapons exhibited that fateful day. However, the gun and cartridge that finally ended that gun fight was an "anemic" 38 Special cartridge in a 2in snub nose revolver, and a well placed head shot.

This is not to say I would only carry a 10mm Auto, or that you should only take head shots, or that a heavily clothed bad guy won't shrug off a 9mm. It is to say, the ideal weapon in a violent situation in which you are forced to take action is the weapon you have with you. You must be expert in it's operation, expert in bullet placement, and by all means, take whatever actions necessary until the threat no longer exists.

Heavy clothing a concern? Yep. Will the bullet type make a huge difference? I don't have an absolute answer, but not in my opinion - which is worth exactly what you paid for it...

 

[Manco]

From what you've demonstrated in terms of mathematical capability, I believe that you might get alot out of Duncan MacPherson's book, "Bullet Penetration: Modeling the Dynamics and Incapacitation Resulting from Wound Trauma". MacPherson is a real, honest to goodness, MIT educated "rocket scientist" (he worked on the Mercury program; calculated trajectories and orbital mechanics for the orbital vehicles)

That's exactly the sort of thing I've been looking for. Thanks for the reference!

It is interesting that you mention the FBI's 12 inch penetration requirement as being "a bare minimum". MacPherson addresses the issue in his book stating that setting a "hard" algorithmic requirement of 12 inches is a step in the wrong direction and he suggests that a "soft" algorithm (in essence a preferred range not an immovable threshold) be adopted to qualify what is acceptable and unacceptable bullet penetration.

Well, that's true as long as one has the knowledge and techniques by which to rate each load on the whole. The FBI, of course, are still haunted by the specter of the Miami shootout and want to stay on the safe side of the penetration issue.

Even so with this capablility, there are so many more variables that come into play in actual bullet performance in real-life shootings that believing this to be "the answer" is simply an exercise in fallacious thinking.

In a service pistol caliber, I think there can never be "the answer" even if you could take literally every factor into account with absolute accuracy, because different people and agencies are going to have different standards or level of comfort with the resulting statistics. Thus the "caliber war" rages on, but people should at least know that doubling the diameter of a bullet does not simply double the odds of incapacitation (and probably far from it). I can imagine some people believing that.

 

[481]

In a service pistol caliber, I think there can never be "the answer" even if you could take literally every factor into account with absolute accuracy,...

I agree with you.

My personal "answer" has been to follow the recommendations made by MacPherson (on page 298 of his book) when it comes to the selection of ammunition for the purpose of self defense.

Those "guidelines" are:

1. Average penetration should be about 14 inches
2. Velocity should be between 800 fps and 1,000 fps
3. Weight should be the maximum practical for the caliber (147, 180, 230 grains in 9mm, .40/10mm, .45 ACP respectively)

Works for me, but YMMV.

 

[Manco]

I'm assuming you're asking about penetration through several layers of clothing, and that is a valid concern.

I think the concern of most people regarding several layers of clothing is not penetration per se, but whether thick layers of clothing could clog JHPs and make them behave like FMJs instead of expanding. The latest premium JHPs from the major manufacturers are all pretty reliable in this regard these days, and even when they fail it's not like they're going to bounce off--you'll still get at least FMJ performance.

However, I don't believe we can ever truly be prepared for every possible scenario. We can just be as prepared as we possibly can. What if the attacker is behind a barrier, what if he's broadside instead of facing directly, what if the attacker is morbidly obese with multiple layers of clothing, the what if's can go on for quite some time.

Well, we can still talk about the performance of specific bullet design characteristics against these issues so that we're at least a little more knowledgeable about our options. For example, if you want to penetrate some thin but hard barriers and still use JHP, then you'll want a bonded design, preferably in a larger, heavier caliber since it displaces less (this rules out all-copper bullets such as DPX for me, however cool they may seem). On the other hand, really large and/or obese people are going to be a penetration challenge for JHPs that expand quickly and a lot, which are normally considered virtues. With waistlines constantly on the rise, maybe people should raise their standards for penetration; maybe FMJ has more merit than most of us give it credit for, in that it can reach the spine, aorta, or vena cava of a big fat perp with a COM hit when some fancy JHPs might not get the job done.

There is no magic bullet, caliber, or weapon that will dispose of any and all threats we may run across. Which goes back to my original statement - bullet placement is the key ingredient, and the only "magical" component if one actually exists.

Look at it this way, a .22 LR to my eye would put me down cold, no doubt, but a .22 LR to the front of my gut, close to the center horizontally, would almost certainly just piss me off. On the other hand, a 9mm FMJ with identical bullet placement would probably penetrate to my spine in the second case and drop me quickly in both cases.

Heavy clothing a concern? Yep.

In what way do you mean?

Will the bullet type make a huge difference? I don't have an absolute answer, but not in my opinion - which is worth exactly what you paid for it...

It depends on how you define "huge." All I can say is that sufficient penetration is required to reach as many vital structures as possible, and falling short can potentially make a "huge" difference. Beyond that, differences are not "huge" until you get to the larger rifle calibers, but still may be worthwhile.

 

[Manco]

My personal "answer" has been to follow the recommendations made by MacPherson (on page 298 of his book) when it comes to the selection of ammunition for the purpose of self defense.

Those "guidelines" are:

1. Average penetration should be about 14 inches
2. Velocity should be between 800 fps and 1,000 fps
3. Weight should be the maximum practical for the caliber (147, 180, 230 grains in 9mm, .40/10mm, .45 ACP respectively)

Works for me, but YMMV.

I currently use Winchester PDX1/Ranger Bonded .40 S&W 180gr, which gets about 15" of penetration at a velocity of 1025 fps, so coincidentally that's a pretty good match. Personally, I prefer heavy-for-caliber bullets because they're more "resilient" in general--they are less affected by barriers, tend to penetrate more, and maintain velocity and momentum better. Obviously additional mass is only advantageous to a point, but 147, 180, and 230 grains--given the proper bullet construction--are great for the common service calibers.

 

[481]

I currently use Winchester PDX1/Ranger Bonded .40 S&W 180gr, which gets about 15" of penetration at a velocity of 1025 fps, so coincidentally that's a pretty good match. Personally, I prefer heavy-for-caliber bullets because they're more "resilient" in general--they are less affected by barriers, tend to penetrate more, and maintain velocity and momentum better. Obviously additional mass is only advantageous to a point, but 147, 180, and 230 grains--given the proper bullet construction--are great for the common service calibers.

Sounds like a great choice and your reasoning is sound.

I carry the 9mm Hornady 147 gr. TAP "CQ" XTP JHP. Good for 15.25 inches after "heavy clothing" and expansion to ~1.5x caliber. Muzzle velocity is ~975 fps.

 

[hinton03]

Many people believe that the 45 ACP with a 230 grain projectile is the gold standard as a SD combination; I myself believe this to be the best combination for me.

However, in contradiction of MacPherson's recommendation I fully believe a medium weight bullet at a very high velocity (e.g. 125 grain 357 Mag) is a much more devastating SD combination. To me this is evidenced by many recorded cases showing the 357 Mags performance in actual shootings and my own experience killing game with medium weight high velocity calibers.

The development of modern bullet designs and materials nearly eliminates issues associated with bullet fragmentation and case seperation at high velosity. I choose the 45 ACP because it best meets my criteria for penetration, controlability, bullet diameter, capacity and platform, but if I only had one shot to do the job it would be the 357 Magnum throwing a quality 125 grain JHP out at 1400 FPS.....I wouldn't even think twice about the math.

 

[Manco]

However, in contradiction of MacPherson's recommendation I fully believe a medium weight bullet at a very high velocity (e.g. 125 grain 357 Mag) is a much more devastating SD combination. To me this is evidenced by many recorded cases showing the 357 Mags performance in actual shootings and my own experience killing game with medium weight high velocity calibers.

Perhaps the recommendations were in regard to what was best for calibers that are considered easier to shoot, namely "service" calibers. At least that was my assumption when I discussed it. Not that .357 Magnum is all that hard to shoot since many common loads are on the light side, but a moderate-to-hot load could be considered a different class of caliber. When used for self-defense, a heavy bullet in this caliber might have excessive penetration (too much of a good thing) even if it expands, making medium or light bullets the preferred loads for human targets. Of course, this also maximizes the kinetic energy that is imparted to the target, which with most pistol calibers is a controversial subject in itself as to its efficacy.

I choose the 45 ACP because it best meets my criteria for penetration, controlability, bullet diameter, capacity and platform, but if I only had one shot to do the job it would be the 357 Magnum throwing a quality 125 grain JHP out at 1400 FPS.....I wouldn't even think twice about the math.

Hmmm...that's a fairly light .357 Magnum load, actually--it's possible to get nearly the same performance with a hot 9mm+P load, and with the right loads .357 SIG, .40 S&W, and .45 ACP can all exceed it in kinetic energy at standard pressure. Like you, I think I'll stick with slower, heavier bullets, which give me all the penetration I need with less blast and flash. And if I only had one shot with a handgun, I'd make it a hot .357 Magnum load with a 125 grain bullet or maybe a .500 S&W Magnum.

 

[481]

However, in contradiction of MacPherson's recommendation I fully believe a medium weight bullet at a very high velocity (e.g. 125 grain 357 Mag) is a much more devastating SD combination. To me this is evidenced by many recorded cases showing the 357 Mags performance in actual shootings and my own experience killing game with medium weight high velocity calibers.

hinton03,

Many years of superb performance by the .357 125 gr. JHP supports your assertion.

Remember though, that MacPherson's recommendation also gives considerable value to the controlability of the load being used.

MacPherson's research and the criteria Mc (a "dimensionless" ratio), demonstrates that as bullet weight decreases, penetration declines commensurately requiring an increase in velocity in order to achieve the similar Mw (wound cavity mass which is a function of penetration depth) as a bullet having a greater weight (and a higher sectional density) and this requires subjecting the operator of the gun to more recoil in order to obtain equal performance, in this case; Mc; with the lighter bullet.

You wisely chose such a combination (perhaps without even reading MacPherson's book?)...

I choose the 45 ACP because it best meets my criteria for penetration, controlability, bullet diameter, capacity and platform...

...because it provides you all the penetration (largely, but not wholly, dependent upon the high sectional density of the 230 gr. bullet) and the Mw that accompanies it, while remaining a comfortable and controlable enough selection for you to perform as well as you can when you need to do so.

Mc is all about balancing controlabilty (ie: "recoil") against terminal performance (ie: penetration and its related paremeter, Mw).

 

[hinton03]

I choose the 230 grain HST JHP for exactly the combination of reasons you lay out.

The 357 Mag does produce a lot of recoil but since we were discussing service loads I assumed a service weight revolver. I am a big fan of the 357 but choose to shoot full power loads in my Python and M27 only. I choose 38 Special loads in my 357 rated J frames.

 

[HB]

Ricochet? I'm unaware of ANY data to support the belief that Round Nose and FMJ bullets exhibit different ricochet characteristics. If you have data, please share.

I don't have any real data but it seems reasonable that JHP would ricochet less. There is exposed "teeth" that could more easily get stuck in the ground, walls, etc. Pin shooters choose HPs over FMJ because of this.

HB

 

[481]

However, in contradiction of MacPherson's recommendation I fully believe a medium weight bullet at a very high velocity (e.g. 125 grain 357 Mag) is a much more devastating SD combination. To me this is evidenced by many recorded cases showing the 357 Mags performance in actual shootings and my own experience killing game with medium weight high velocity calibers.

hinton03,

BTW, your assertion is hardly contrary to MacPherson's parameter, Mc. (where Mc = Mwound cavity mass/Mprojectile)

In fact your statement is in total agreement with the concept of Mc as it correlates in a "general sense" by indicating that the .357 125 gr. JHP @ 1450 fps is a "medium weight bullet at a very high velocity" (its sectional density is 0.140505) whereas the .45 ACP 230 gr. JHP @ 825 fps (with a sectional density of 0.161181) is a heavier bullet at much lower velocity.

The momentum generated by each round demonstrates this quite clearly...

A .357 125 gr. JHP @ 1450 fps = 0.804775 ft-lb/sec

A .45 230 gr. JHP @ 825 fps = 0.842516 ft-lb/sec

...in that both cartridges will produce very similar (almost equal, with a difference of only ~4.7%) recoil in guns of equal mass while producing very similar values of Mw.

 

[spaladino]

Manco, you have very valid points, and I do not disagree with any of them.

I'm looking at this more from the perspective of "I have chosen this specific weapon, in this specific caliber, with this specific cartridge to protect my life". All of these factors play a role, some more significant than others. If I could envision "perfect", it would be a 6" 357 Magnum with 2 rounds of 38 Special +P 158gr semiwadcutter hollowpoints, backed by 4 rounds of 357 Magnum 125gr jacketed hollow points, with a speedloader of more 357 Magnum cartridges that I could fit it my front pants pocket. Unfortunately, it stays beside my bed because my pants aren't that big... though they seem to be ever expanding with age.

In shooting scenarios that I've heard, and experienced personally, JHPs, in general, perform closer to the ideal versus FMJ. But this is subjective - there are corner cases and exceptions in all things. Penetration is penetration. If the bullet must traverse a leather bomber jacket, a denim undercoat, and a wool sweater to get to the intended vitals, it is still the penetration that matters, absolutely true. That's why I don't carry a 22LR, 32 or 380ACP. Not because they haven't been effective in the past, it's just I'm not confident in their ability to penetrate to the vitals of the bad guy in "average" situations, and my ability to put one in the eye socket 100% of the time in scenarios that I would evaluate may have penetration issues. Though if given the option of a stick or a 380 in a gun fight, I would choose the 380 every time, don't get me wrong, for those 380 fans out there...

What I am looking for in bullet construction is deformation and increasing the likelihood of expending all available energy inside the intended recipient, not in the surrounding countryside, in the "average" scenario. If the bullet fragments or yaws inside the intended target, I'm ok with that. It increases tissue damage, therefore bloodloss, therefore decreasing the expiration timer. Overpenetration, in my eyes >12-15in, increases the chances that I will expend energy in the wall behind the bad guy, unless he's standing broadside, morbidly obese, etc. Hence, FMJ is not my preferred choice in the calibers or weapons that I carry. Though there is obviously the thought that 2 holes (entry and exit) are better than one for bloodloss purposes. I'm just not of that opinion.

Depending on the day and what I'm carrying, these are my preferred go-to cartridges. Generally, I prefer the light to mid-weight bullets at >1000fps to promote faster deformation of the bullet upon entry, knowing that the higher fps/forward momentum will balance for the lighter mass. For the less brisk cartridges <1000fps, I prefer heavier, again, trying to balance penetration and keep the bullet in the bad guy where it can do the most damage.

45 ACP: Federal 45 ACP 230 grain Hydrashok jacketed hollow point (P45HS1)
40 S&W: Winchester 40 S&W Silvertip 155 grain jacketed hollow point (X40SWSTHP)
9mm Luger: Federal 9mm Luger 115 grain jacketed hollow point (9BP)
357 Magnum: Federal .357 Magnum 125 grain jacketed hollow point (357B)
38 Special: Remington .38 Special +P 158 grain lead semi-wadcutter hollow point (R38S12)

 

[Manco]

I'm looking at this more from the perspective of "I have chosen this specific weapon, in this specific caliber, with this specific cartridge to protect my life". All of these factors play a role, some more significant than others. If I could envision "perfect", it would be a 6" 357 Magnum with 2 rounds of 38 Special +P 158gr semiwadcutter hollowpoints, backed by 4 rounds of 357 Magnum 125gr jacketed hollow points, with a speedloader of more 357 Magnum cartridges that I could fit it my front pants pocket.

Personally, I've never been keen on mixed loads for various reasons (except perhaps on autocannons for a combined effect during rapid fire), including always wanting to know what to expect without having to think about it. The only thing I worry about at all is whether I have the right trade-off between penetration and expansion, and I think I've erred enough on the side of penetration to account for nearly anybody capable of walking and wielding a firearm; I figure that the rare assailant who is even thicker probably won't be able to duck a head or upper chest shot.

Is there any particular reason you consider a mixed load ideal?

What I am looking for in bullet construction is deformation and increasing the likelihood of expending all available energy inside the intended recipient, not in the surrounding countryside, in the "average" scenario. If the bullet fragments or yaws inside the intended target, I'm ok with that. It increases tissue damage, therefore bloodloss, therefore decreasing the expiration timer. Overpenetration, in my eyes >12-15in, increases the chances that I will expend energy in the wall behind the bad guy, unless he's standing broadside, morbidly obese, etc. Hence, FMJ is not my preferred choice in the calibers or weapons that I carry.

Same here, pretty much, except that I'm quite willing to risk some overpenetration in the average case in order to handle the majority of above-average cases. Like I said or implied in a previous post, I there is a lot of vital tissue that lies deep in the body relative to a frontal hit, and sometimes hard barriers can play a role, as well. Greater expansion would increase the probability and amount of wounding by a modest but meaningful amount, but in my estimation, does not make up for marginal penetration. We're not far apart in what we think is optimal, actually, although we might err on different sides of the same boundary.

Though there is obviously the thought that 2 holes (entry and exit) are better than one for bloodloss purposes. I'm just not of that opinion.

Neither am I because it doesn't matter whether they bleed externally or internally. I just want the bullet to reach every vital tissue or structure it can, and the spinal column/aorta/vena cava is a major one that lies behind gobs of skin, fat, muscle, and the intestines and their contents. A hit anywhere on that column is probably an instantaneous stop followed by a highly probable rapid death.

Depending on the day and what I'm carrying, these are my preferred go-to cartridges. Generally, I prefer the light to mid-weight bullets at >1000fps to promote faster deformation of the bullet upon entry, knowing that the higher fps/forward momentum will balance for the lighter mass.

Faster deformation usually means less penetration per the amount of energy in the bullet. Like I said, we err on different sides of the same boundary. Other considerations are that heavier bullets tend to maintain momentum and therefore penetration better over distance and through barriers, as well as stay truer to their original trajectory after hitting barriers. Many folks don't take barriers into consideration, but I plan to aggressively shoot at any crook who mistakes concealment for cover--hiding behind furniture might work in western movies but it won't save anybody who breaks into my house.

That said, a caliber like .357 Magnum gives you a larger margin over other common self-defense calibers, so you can do pretty much whatever you want with it.

For the less brisk cartridges <1000fps, I prefer heavier, again, trying to balance penetration and keep the bullet in the bad guy where it can do the most damage.

Makes sense to me.