Cartridge Size vs. Ballistics - Bigger not Necessarily more Powerful?

Cartridge Size vs. Ballistics - Bigger not Necessarily more Powerful?

This is a discussion on Cartridge Size vs. Ballistics - Bigger not Necessarily more Powerful? within the Defensive Ammunition & Ballistics forums, part of the Defensive Carry Discussions category; I never paid much attention to pistol ammo before buying our handguns recently. I was sort of puzzled by the relative size difference between the ...

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    Member Array Slider51's Avatar
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    Cartridge Size vs. Ballistics - Bigger not Necessarily more Powerful?

    I never paid much attention to pistol ammo before buying our handguns recently. I was sort of puzzled by the relative size difference between the .38 SPCL and the 9mm rounds. To the untrained eye, the .38 brass is nearly twice the length, and thus is seemed to me the ballistics against the 9mm should be the other way around from what they actually are.

    I looked at both our FMJ target ammo and our protection ammo. Bullet weight is relatively close between the two calibers in both types of loads, yet despite the smaller architecture of the 9mm cartridge, it outperforms the .38 in both FPS and Energy.

    With all the extra room for powder in the .38, why do the numbers look the way they do? Are the mfrs using different powder blends between the two? I thought it might be that since the .38 is an older caliber and it needs to work safely in older guns, the mfrs sort of "de-tune" the round so as not to damage older weapons (???) They have to stick with the basic architecture (brass length, etc.) to fit the weapon, but can't make it as hot as the 9mm due to structural issues with the older guns? Is that the case, or am I missing something?

    The photo shows both our target ammo and our PP ammo, with the basic test ballistics taken off the respective boxes. This is basically nothing more than a curiosity on my part, but I am inquisitive and would like to figure this out.

    Thanks to anyone who can explain this to me.

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    Member Array lyodbraun's Avatar
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    Im pretty sure it has to with the pressure thats generated in the chamber, the 9mm has something like 40,000 psi and the .38spc has half that ?? around 20,000psi... more pressure equals more velocity... to propel that bullet.. ?? but I could be wrong ??? correct me if I am ?? please

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    Member Array DonPablo_VA's Avatar
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    Yes powder blends are a big part of it. When you put more/different powder blends into a .38 it becomes a .357 Magnum basically. To me that's why the 9MM is a good cartridge, that when loaded with well designed hollow points and driven to +P or +P+, it can rival lower end .357 Magnum performance.

    DP

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    VIP Member Array Kilowatt3's Avatar
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    The .38 Special was originally designed as an improvement upon the .38 Long Colt - a black powder cartridge. Someone will correct me if I'm wrong, but I'd bet that the larger case capacity was needed to get the desired performance out of a black powder charge. There may also have been an intent to make it a tad longer than the LC so that it wouldn't fit in an older .38 LC gun that might not be able to handle the increased pressure (same reasoning as making the .357 Mag 1/8" longer than a .38 Spc).

    The 9mm Luger is only about 6 years younger than the .38 Spc, but it was designed for smokeless powder from the get-go, so it did not require the case capacity to get pretty comparable performance (plus, it generally fired a lighter bullet).
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    Jim
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    "With all the extra room for powder in the .38, why do the numbers look the way they do? Are the mfrs using different powder blends between the two? I thought it might be that since the .38 is an older caliber and it needs to work safely in older guns, the mfrs sort of "de-tune" the round so as not to damage older weapons (???) They have to stick with the basic architecture (brass length, etc.) to fit the weapon, but can't make it as hot as the 9mm due to structural issues with the older guns? Is that the case, or am I missing something?"


    Nope, you figured it out quite accurately.


    .38 Special
    (.38 Smith & Wesson Special, .38 Colt Special)

    The .38 Special dates from 1899 (not 1902 as many references suggest) and represents an effort by Smith & Wesson to provide enhanced performance characteristics over the other .38 caliber cartridges of the day. These other cartridges would have been the .38 S&W, .38 Short Colt, and .38 Long Colt. along with a .38 rim fire cartridge or two. In particular Smith & Wesson sought a ballistic improvement over the military issue .38 Long Colt cartridge with a view to garnering future military contracts.

    The .38 Long Colt offered a 150 grain bullet over 18 grains of black powder with a supposed muzzle velocity of 750 fps. The .38 Special is effectively a lengthened .38 Long Colt cartridge, and originally provided a heavier 158 grain bullet over 21 1/2 grains of black powder with a muzzle velocity increase of about 100 fps over the Colt round. It could be said that the .38 Special was to the .38 Long Colt what the .357 Magnum is to the .38 Special. Both the .38 Long Colt and the .38 Special were almost immediately treated to the various smokeless powders then coming into use, both by factory ammunition providers and handloaders. Neither cartridge really required the available case capacities for the smokeless powders that came into use, that capacity being necessary for the original propellant which was black powder. Because of the original design parameters of the revolvers chambered for the .38 Special, pressure levels have always been held fairly close to black powder loadings or no more than about 20,000 psi.

    The .38 Special cartridge case could have easily been utilized to create the performance characteristics that became the 357 Magnum. The .357 Magnum case's slight increase in length has more to do with keeping it out of .38 Special revolvers than any need for additional case capacity for the enhanced performance characteristics of the round.

    9mm (9X19, 9mm Parabellum, 9mm Luger)

    The 9mm originated in 1902 when Georg Luger opened up his 7.65 Luger cartridge to accept 9mm or .355" diameter bullets. Apparently it was Luger who graced the cartridge as the 9mm Parabellum, taken from the Latin "para bellum" translated "for war." The original loading has been variously described as a 123 grain or 124 grain jacketed truncated cone bullet with a muzzle velocity of 1200 fps. This original ammunition was apparently fairly "hot" and loaded to high pressures. The 9mm was designed around the use of smokeless powders so didn't require the outsized case capacity as is possessed by the .38 Special. The 9mm was designed to operate at fairly high pressures of around 38,000 psi.

    In the early years of the 20th century, the United States, England, and several other nations were interested in Luger's pistol design but desired a larger, heavier bullet. In response to potential customer's demands and because he was seeking lucrative contracts, Luger simply created a slightly tapered case out of his bottleneck 7.65 Luger cartridge case that accepted a 9mm bullet. United States military trials, conducted in 1903, were among the very first recipients of pistols chambered for the new 9mm cartridge. The German Navy first adopted the 9mm Luger as standard in 1904, beating out the German Army's acceptance of the 9mm by four years.

    The two cartridges are very similar in both age and performance characteristics. The .38 Special was designed around the propellant technology represented by black powder. It could be readily adapted to use with smokeless powders but it took the .357 Magnum to completely benefit of the pressures generated by a full case of smokeless powder. Both the 9mm and it's parent cartridge the 7.65 Luger fully embraced the characteristics of smokeless powder developments from drawing board to the first cartridges test-fired.

    Only personal opinion but I consider the modern 9mm and .38 Special to be comparable in performance and the .357 Magnum to be a distinct step up.
    MJB_17, sensei2, Slider51 and 1 others like this.
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    Kilowatt3 pops in and says it all succinctly while I go beating around the bushes.
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    Charter Member of the DC .41 LC Society "Get heeled! No really"

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    That's what I love about this forum. There isn't a question you can ask that doesn't get answered with good data behind the reply. Thanks to everybody, and especially Kilowatt3 and bcgilvray for the great history lesson. Looks like I was close to having it figured out, but the early black powder origins was something I wasn't up on.

    Too bad it would present a danger to older weapons, it'd be interesting to see the numbers on a .38 SPCL loaded up with the same blend as the 9mm. Of course, maybe the modern weapons chambered for .38 SPCL wouldn't stand up to such a load either.

    Thanks for the replies....

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    Some .38 Special Velocity Tests

    Three .38 Special Handloads

    Four High-Performance .38 Special Handloads


    A personal effort, conducted over the space of about a year. Mostly handloads gleaned from loading manuals of all sorts along with a few factory load tests. I like the .38 Special best when it is used with bullets on the heavier end of the bullet weight range generally applicable to the cartridge.

    Using 9mm load data wouldn't yield the same results in the .38 Special cartridge as it does in the 9mm.


    Hoping to do a .357 Magnum load test in the spring.
    Charter Member of the DC .41 LC Society "Get heeled! No really"

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    VIP Member Array pittypat21's Avatar
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    something something.... .45...something something

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    Member Array Slider51's Avatar
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    Quote Originally Posted by Slider51 View Post
    I looked at both our FMJ target ammo and our protection ammo. Bullet weight is relatively close between the two calibers in both types of loads, yet despite the smaller architecture of the 9mm cartridge, it outperforms the .38 in both FPS and Energy.

    .....the .38 is an older caliber and it needs to work safely in older guns, the mfrs sort of "de-tune" the round so as not to damage older weapons (???) They have to stick with the basic architecture (brass length, etc.) to fit the weapon, but can't make it as hot as the 9mm .....
    Looking back at the photo I attached I did notice something I hadn't before. I first picked up on the seeming upside-down ballistics numbers vs. cartridge size on the target loads and didn't really focus on the SD round numbers as much. Hornady's numbers on the .38 SP show that they have in fact "tuned up" the +P comparing pretty close to the 9mm +P in FPS. (1090 vs. 1115 with the 9mm) Obviously the lighter 110gr bullet instead of the FMJ 130gr accounts for some of the closer velocity comparison but even then the energy spread isn't as great as a percentage in the SD rounds as it is in the target rounds. This tells me Hornady has in fact boosted the charge by a greater percentage in the .38 than in the 9mm, so there must be more wiggle room in upgrading the charge in the .38 than I first thought. I'm sure it wouldn't be wise to fire the modern .38 SP +P rounds in an older weapon in any quantity, but this looks like an example of a round that isn't "de-tuned" as much as the target loads are.

    Of course my observations are probably common knowledge to most of you who really get into this stuff, but it was a fun learning exercise for me to explore the performance of these common production rounds that I frequently buy.

    Very interesting reports, bmcgilvray. I can see you've been doing this stuff for a long time and your knowledge base is amazing. Thanks!

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    Senior Member Array sensei2's Avatar
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    remember, when you're talking about "power" in a firearm cartridge, you're generally talking about foot-pounds of energy, and because of the way this is calculated, bullet speed or velocity is especially important.

    in general, lighter weight bullets that are driven faster will have higher energy figures than slower, heavier bullets IN THE SAME CALIBER. for example the 155 grain loads in .40S&W will almost always have higher energy figures than the slower, heavier 180 grain .40 loads. this does NOT mean that the lighter bullets are better man stoppers - they may or may not be - you have to evaluate each case individually (IMO).

    and to this somewhat 'trained' eye, .38 Special also 'looks' like it should be more powerful than 9mm, but it's not (usually).

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    Member Array Slider51's Avatar
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    Quote Originally Posted by sensei2 View Post
    remember, when you're talking about "power" in a firearm cartridge, you're generally talking about foot-pounds of energy, and because of the way this is calculated, bullet speed or velocity is especially important.

    in general, lighter weight bullets that are driven faster will have higher energy figures than slower, heavier bullets IN THE SAME CALIBER. for example the 155 grain loads in .40S&W will almost always have higher energy figures than the slower, heavier 180 grain .40 loads. this does NOT mean that the lighter bullets are better man stoppers - they may or may not be - you have to evaluate each case individually (IMO).

    and to this somewhat 'trained' eye, .38 Special also 'looks' like it should be more powerful than 9mm, but it's not (usually).
    Of course - because "power" is a linear equation, both velocity and bullet weight are equally important to the outcome. If you were to graph power between two different bullet weights at varying velocities, there will be a point where the two lines intersect, the theoretical point where both cartridges have the same "power".

    In my way of thinking, projectile weight has a greater role in stopping power than velocity. In my own experience, using deer hunting as a real world test, at ranges 50 yards and under I have had more single shot quick kills with a 12ga slug than with my 30.06. Of course this changes dramatically as range increases, but the massive shock of the big yet slow slug is hard to beat with a high velocity light bullet at shorter distances.

    I totally agree with you - there are a whole list of other factors involved in stopping power case by case than just bullet weight and velocity.

    Thanks

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    VIP Member Array Kilowatt3's Avatar
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    Quote Originally Posted by Slider51 View Post
    Of course - because "power" is a linear equation, both velocity and bullet weight are equally important to the outcome. If you were to graph power between two different bullet weights at varying velocities, there will be a point where the two lines intersect, the theoretical point where both cartridges have the same "power"...
    Allow me to nit-pick...

    The term "power" (as opposed to "energy") is actually meaningless when applied to a bullet. Power is the rate of transfer of energy per unit of time. Since any bullet either stops, or passes through its target within a couple of milliseconds or so, the rate at which energy is transferred is basically irrelevant. When people refer (incorrectly) to how "powerful" a bullet is, the only really quantifiable measure is energy.

    Energy is NOT a linear equation; It is proportional to bullet weight, and proportional to the square of the speed.

    If you graph energy vs. velocity for two different bullet weights, the curves will never intersect. At any given velocity, a heavier bullet will always have more energy. At any given bullet weight, a higher velocity will always yield higher KE. I believe that what you meant to say was that a given energy can be achieved with either a heavy bullet at a lower velocity, or a lighter bullet at a higher velocity.

    Quote Originally Posted by Slider51 View Post
    In my way of thinking, projectile weight has a greater role in stopping power than velocity...
    Well, this could be argued ad infinitum, since "stopping power" is not really quantifiable. The next best thing would have to be KE, which is more dependent upon velocity than weight.

    Quote Originally Posted by Slider51 View Post
    I totally agree with you - there are a whole list of other factors involved in stopping power case by case than just bullet weight and velocity...
    Definitely agree with you here. I'm very inclined to think that bullet diameter and bullet design are BIG factors, as evidenced by your experience with 12 ga slugs and the experience of several board regulars with LSWC bullets in .38/.357 handguns. At typical hunting distances, the 12 ga slug has probably half the KE of a .30-06, but it does a number on deer. At typical SD distances, a LSWC .38 is pretty unimpressive on paper, but anecdotal evidence suggests it's pretty effective, even when compared with bullets that have half again as much KE.

    So, take your pick:
    A heavier bullet is better.
    A faster bullet is better.
    A larger caliber bullet is better.
    A sharp-shouldered bullet is better.
    An expanding bullet is better.
    A good combination of the above is best.
    Regards,
    Jim
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    Member Array Slider51's Avatar
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    Quote Originally Posted by Kilowatt3 View Post
    Allow me to nit-pick...

    The term "power" (as opposed to "energy") is actually meaningless when applied to a bullet. Power is the rate of transfer of energy per unit of time. Since any bullet either stops, or passes through its target within a couple of milliseconds or so, the rate at which energy is transferred is basically irrelevant. When people refer (incorrectly) to how "powerful" a bullet is, the only really quantifiable measure is energy.

    Energy is NOT a linear equation; It is proportional to bullet weight, and proportional to the square of the speed.

    If you graph energy vs. velocity for two different bullet weights, the curves will never intersect. At any given velocity, a heavier bullet will always have more energy. At any given bullet weight, a higher velocity will always yield higher KE. I believe that what you meant to say was that a given energy can be achieved with either a heavy bullet at a lower velocity, or a lighter bullet at a higher velocity.

    Well, this could be argued ad infinitum, since "stopping power" is not really quantifiable. The next best thing would have to be KE, which is more dependent upon velocity than weight.

    Definitely agree with you here. I'm very inclined to think that bullet diameter and bullet design are BIG factors, as evidenced by your experience with 12 ga slugs and the experience of several board regulars with LSWC bullets in .38/.357 handguns. At typical hunting distances, the 12 ga slug has probably half the KE of a .30-06, but it does a number on deer. At typical SD distances, a LSWC .38 is pretty unimpressive on paper, but anecdotal evidence suggests it's pretty effective, even when compared with bullets that have half again as much KE.

    So, take your pick:
    A heavier bullet is better.
    A faster bullet is better.
    A larger caliber bullet is better.
    A sharp-shouldered bullet is better.
    An expanding bullet is better.
    A good combination of the above is best.
    Pick away, KW3. I obviously didn't dust off my math skills well enough before I made that statement. (Missed the fact that the energy formula involves the velocity squared). I also grabbed the term "power" from sensei2's reply when we were actually talking about energy. "Power factor" is a linear equation (weight x velocity / 1000) and thus the confusion. Dang I hate making mistakes. But your points are well taken and I appreciate the correction with appropriate humility.

    My example with the 12ga slug I believe points out the obvious that "better" is always dependent on the actual application, as did your list at the bottom and sensei2's example with the .40 cal. Guess we all agree on that one. It should also be said that applying results from a hunting environment to a SD discussion or vice versa is like picking an orange from an apple tree.

    Thanks!

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    Member Array Slider51's Avatar
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    Quote Originally Posted by Kilowatt3 View Post
    The term "power" (as opposed to "energy") is actually meaningless when applied to a bullet. Power is the rate of transfer of energy per unit of time. Since any bullet either stops, or passes through its target within a couple of milliseconds or so, the rate at which energy is transferred is basically irrelevant. When people refer (incorrectly) to how "powerful" a bullet is, the only really quantifiable measure is energy.


    I'm very inclined to think that bullet diameter and bullet design are BIG factors, as evidenced by your experience with 12 ga slugs and the experience of several board regulars with LSWC bullets in .38/.357 handguns. At typical hunting distances, the 12 ga slug has probably half the KE of a .30-06, but it does a number on deer.
    A few nits of my own to pick:

    ".....at ranges 50 yards and under I have had more single shot quick kills with a 12ga slug than with my .30-06. Of course this changes dramatically as range increases, but the massive shock of the big yet slow slug is hard to beat with a high velocity light bullet at shorter distances."

    Laying aside the scientific definition of "power" or "stopping power", the terms are still acccepted as a way to talk about the ability of a given projectile to produce the desired effect, as in a quick, humane single shot kill. I used the term "shock" which boiled down really refers to how efficient the deforming projectile is in transferring maximum energy in a very short period of time to a live target (the deer in this case). Here is a case where KE doesn't make as much difference as projectile shape, weight, expansion, and the transfer of the largest percentage of the available energy. Call it "shock", "shocking power", "killing capability" or just "power", it is a form of energy transfer that hunters look for.

    I think defined in this way, "power" and the rate at which the energy is transferred is not meaningless or irrelevant, it rather is the point entirely. In the case of the 12ga slug versus the .30-06 bullet, I've often been glad that the slug expanded quickly (milliseconds) to a very large size and dumped its entire energy load to the animal within say 3"-6" of penetration; because my shot wasn't necessarily perfectly targeted to the heart. The concussive force and tissue expansion providing enough trauma to stop the heart. With the .30-06, the same shot misplacement has resulted in a through and through wound path closely missing the heart/aorta in which case a much lower percentage of the higher KE was efficiently transferred to the animal. A slower kill often requiring a second shot or even tracking a wounded animal, all less humane.

    Oh, and yes ..... "I believe that what you meant to say was that a given energy can be achieved with either a heavy bullet at a lower velocity, or a lighter bullet at a higher velocity." ... this was exactly what I was trying to say, albeit with faulty calculations to back it up.

    Thanks KW3 - Like that you make me think - as I get older that's often a hard thing to do..

    Slider

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