9mm vs. 38 Special


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TeamPrecisionIT
March 20, 2009, 11:03 AM
This isn't really a caliber war, more of a need for an explanation. I have a 9mm pistol and a .38 Special revolver and I was shooting them both at the range yesterday and made an observation. I noticed that the .38 Special cases were significantly longer, maybe just a little less wide but according to the data, the .38 loses quite a bit on power and speed. How is that possible when there is much more room for powder in the .38 case against the 9mm? Maybe some of you guys that have been around longer can help me to understand this a little better.

Damian

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gmhamilton3
March 20, 2009, 11:27 AM
Short version.
SAAMI pressure ratings for the 9mm are 35,000 PSI for standard and 38,500 for +P. There are no designated SAAMI specs for +P+ that I can find.
The .38 Special, SAAMI pressure for the standard pressure load is 17000 PSI. The +P has a ceiling of 20000 PSI. There are no SAAMI specifications for +P+, but there are some +P+ rounds available in this caliber. 356 to 0.358".
Long version.
http://www.hipowersandhandguns.com/9mm%20vs%2038%20Special.htm

TheVirginian
March 20, 2009, 11:50 AM
This was just covered in another thread. The thread title or specific forum section escapes me. Basically, the 9mm round develops higher pressure, so it's more powerful for its size. It isn't terribly more powerful in the long run however as velocity at muzzle and a short distance will show. since the bullet diameters are the same size, bullet weights can also be the same and again, that makes them pretty equivalent in terms of its ballistic effects on a target. The 9mm is actually a bit hotter as the gmhamilton3 states but it isn't enough to warrant any switch from one round to the other in search of ballistics performance.

The reason the 9mm is short is obviously for fitting more easily into an auto loading magazine. The reason that it is more popular is due to those auto loader magazines having a high capacity.
-Bill

Marlin 45 carbine
March 20, 2009, 12:05 PM
I've shot enough 124gr 9mm+P and 125gr .357mag into wood target mountings to know I don't care to suffer a 'hit' from either one.

ArchAngelCD
March 20, 2009, 12:07 PM
Along with the other correct information above there is more. The .38 Special case is so long because it was originally designed to be loaded with Black Powder. You needed the length to hold enough powder to achieve the desired velocity. When the caliber changed over to smokeless powder it left a lot of the case capacity empty because if you filled it with powder you would easily exceed the pressure ratings, especially for the guns of the time. The 9mm case is so small and the pressures are so high because it was developed for smokeless powder, not black powder.

gmhamilton3
March 20, 2009, 12:10 PM
In addition, the 9mm uses a "hotter" powder primarily to generate high pressures in a 4'' barrels. The .38 just cannot match this performance especially in a 2'' snubby. However performance is relative, both will kill you just as dead. Like you I have both along with a .45 and needless to say all 3 will be around for the next hundred years and for good reason.

BlindJustice
March 20, 2009, 12:49 PM
In the later part of the 19th century before the invention of smokeless powder which generates much more pressure per volume than
black powder the way ammunition makers made more powerful
CARTRIDGES ( a characteristic of aANY cartridge is it's Caliber which most
people use as a term to refer to specific cartrdiges FWIW ) was
to make the cartridges case length longer given the same calber as
it's predecessor. So when Smith & Wesson created the .38 S&W
SPecial cartridge it was a lengthened .38 Long Colt Cartridge HOwever,
the .38 Special as we refer to the cartrdge in a shorened name, was
created in 1899 and the blackpowder charge was 21.5 grains. By
1902, the BP charge was replaced with a lesser amount of smokeless
powder so the original revolver used the same cartrdige in order to not
have to redesn for a shorter new cartridge specifically desgned for
smokeless powder.

Several cartridges can share the same calilber but each cartridge has
a unique case hspae/dimensions.

Randall

Brian Williams
March 20, 2009, 01:37 PM
If you take a 38 Spec case and trim it to the same case capacity as a 9mm you will have the same basic round. In order to make sure you have the same internal capacity, you must fill a 9mm case to the mouth with water and measure that and then shorten a 38 case to whatever length that will hold the same amount of fluid. A 38 case might have a different web thickness or what ever and it might end up as a 9mmx20R instead of a 9mmx19.

I have often thought a 38S&W loaded to it's full potential with today's powders and projectiles in a revolver made with today's materials would be a great combination.

doubs43
March 20, 2009, 02:02 PM
Skeeter Skelton wrote that when he finally was able to lay his hands on a .357 Magnum revolver, he had trouble finding brass but had all the free .38 Special cases he could ever use.

Lyman made (still does) a mold (#358156) for a 158 grain gas-check bullet designed by a man named Ray Thompson. It has two crimping grooves. Loaded with 13.5 grains of 2400 in a .38 Special case and crimped in the lower groove, velocities in the 1200 fps range are achieved in a .357 Magnum revolver. This is a load that Skeeter used a lot and was completely satisfied with.

The above load makes use of the case capacity of the .38 Special to get a velocity close to that of a .357 Magnum. I've used it in a S&W 586 and it's very good in my experience.

CAUTION: DO NOT use this load in a revolver designed for .38 Special only. It's too hot for any revolver that isn't designed for .357 Magnum loads.

Deanimator
March 20, 2009, 03:32 PM
1. .38 Special was designed for black powder and early, less efficient smokeless powders which needed more case capacity.

2. .38 Special is MUCH better with heavier bullets. The heaviest commonly found bullet for the 9x19mm is 147gr. The STANDARD bullet weight for the .38 Special is 158gr., and at one time 200gr. was quite common. I simply don't like light bullets. I won't carry anything but 147gr. bullets in my 9x19mms. I won't carry anything lighter than 158gr. bullets in my .38s and .357s, and always some variation of the 158gr. LSWC-HP "FBI" load.

BlindJustice
March 20, 2009, 09:44 PM
Along the lines of comparing a case built for smokeless powder like the 9mm Parabellum (DOB 1908?) versus the .38 S&W Special (DOB 1899 BP/1902 Smokelss powder changeover ), I'd like to present the .45 ACP ( DOB 1905 )
and it's younger 'brother' the .45 Auto Rim ( DOB 1920) Even though the
.45 Auto RIm was designed for smokeless powder SAAMI keeps it rated at 14,000 PSI same as cartridges that started off designed for BP, like the .45 Colt, .44-40, .38-40, and even the .44 Special. Just what weak guns was the .45 Auto RIm ever chamberd for? Or was it balloon style brass which is
weaker ? WHen did ammo companies stop using the older Balloon style brass?

Rant on...

I've read of several handloaders who put charges of 12-13 grains of
#2400 in .45 AR to giddyup heavy SWCs, and Buffalo Bore just introduced a new loading for .45 AR. a 200 gr. SWC @ 1200 FPS. I've re-adjusted my
thoughts of my custom loaded leadhead 200 gr. SWC @ 1,025 FPS as certainly non +P in .45 ACP, as well as .45 AR for my 625. Heck the .45 AR has an extra thick rim, it's approx. 0.0910" thick for the correct spacing for
the firing pin, a .45 Colt for instance has a rim approx. 0.0615" thick. So, the
AR has extra 'meat' at the base as it is, always has, but did they ever make
AR brass with balloon heads?

ok, rant off...

Randall

jaydubya
March 20, 2009, 10:03 PM
Incidentally, the reason wadcutter bullets are loaded completely within the casing is to take up empty space left by the low powder charges. If this weren't done, the powder would slosh around, effecting burn rate so much that accuracy would be impossible. As it is, and eliminating all outside considerations, wadcutters are probably the most accurate rounds out there.

Cordially, Jack

wanderinwalker
March 20, 2009, 10:05 PM
gmhamilton3 In addition, the 9mm uses a "hotter" powder primarily to generate high pressures in a 4'' barrels. The .38 just cannot match this performance especially in a 2'' snubby. However performance is relative, both will kill you just as dead. Like you I have both along with a .45 and needless to say all 3 will be around for the next hundred years and for good reason.

Just a quick point: They frequently use the exact same powder! I load Win 231 powder into .38 Special and 9x19mm. I actually use less in the bigger .38 case.

What you get is more pressure burning X.XXgr of powder in a .38 case than in a 9mm case. Same charge + smaller space = greater pressure. Also, larger bore rounds do more work with less pressure than smaller-bore rounds.

That said, for tossing 158gr slugs, the .38 trumps the 9mm any day. For 124/125gr loads, I'll take a 9mm +P over a .38 +P. And if you have a .357 revolver, you have a whole new can of worms to open.

BlindJustice
March 21, 2009, 12:44 AM
wanderinwaker and whoever he quoted imo neither make a bit of sense
with rules of physics except yeah a larger bullet moving at the same speed
is more effective.

You put the same amount of the same powder in a larger cartrdge with more space inside and it cannot develop equal pressure, it will be less. you can't change physics.

R-

doubs43
March 21, 2009, 01:19 AM
BlindJustice, the 9mm Luger cartridge was introduced first in 1902 in the "Fat Barrel" Luger, also introduced in 1902.

The .45 Auto-Rim was made to be used in the 1917 US Army revolvers to make the half-moon clips unnecessary. Some of the revolvers were made with a step in each cylinder so that a .45ACP cartridge would work without the clips. In that instance the empties had to be individually pushed out with a pencil or similar object. Some 1917 revolvers were made with a straight cylinder and needed either the clips or the rimmed cases.

BlindJustice
March 21, 2009, 01:45 AM
ONly a very few of the M1917 Colt New Service revolvers were not counterbored for the correct chambering, none of the S&W N-frames were
made the way you incorrectly suggest. It doesn't have anything to do
with the strength of the .45 Auto RIm or how it headspaces via the rim and
not the mouth of the case like the .45 ACP. Doughboys were issued .45 ACP
in boxes where they had 8 half moon clips pre-loaded, two for the M1917 and 6 paired fit into thir bandolier that had three pockets

What does that have to do with the transition of cartrdiges from
blackpowder to smokeless ?

Randall

Blakenzy
March 21, 2009, 02:15 AM
I wonder why we don't see more snubbies in 9mm. Wouldn't it make for more compact pocket guns than .38spl, at least length wise?

Radagast
March 21, 2009, 07:25 AM
Brian Williams: It was pretty much done back in 1989 with the 9mm Federal and the Charter Arms Pit Bull. Unfortunately the 9mm Federal would chamber in old .38 S&W top break revolvers and was quickly pulled from the market.

Blakenzy Yes it would, but this would mean redesigning/engineering the revolvers to have a shorter window for the cylinder. The J & J Magnum frames are a stretch of the old I frame that the .38 S&W was chambered in many years ago. From the viewpoint of Ruger & S&W it is more viable to run with their standard frames, rather than introduce a new one. There have been short runs of 9mm chambered guns but they haven't built up any demand, possibly due to the need for moon clips.
IIRC Taurus announced a new 9mm snubbies with a short frame a couple of SHOT Shows ago, but it never made it to market in any quantity.

BlindJustice
March 21, 2009, 10:14 AM
+1 Radnagast

R-

Walkalong
March 21, 2009, 10:32 AM
In addition, the 9mm uses a "hotter" powder primarily to generate high pressures in a 4'' barrels. The .38 just cannot match this performance especially in a 2'' snubby.It's not a "hotter" powder in the 9MM, it's just loaded to more pressure. The .38 could use any powder available and still not match the 9MM because it is loaded to a much lower pressure level, as has been posted.

Deanimator
March 21, 2009, 10:50 AM
Incidentally, the reason wadcutter bullets are loaded completely within the casing is to take up empty space left by the low powder charges.
That's A reason, not the ONLY reason.

I have a .38 Special M1911. The ONLY ammunition it can use is flush seated wadcutters. Anything longer won't fit in the magazine, much less feed.

I once went to an indoor range with a 25 yard section to zero some guns for Camp Perry, including the aforementioned Giles .38. The guy at the counter told me I couldn't shoot lead bullets, but offered to sell me some jacketed hollow points to shoot in the Giles. I just picked my stuff up and drove to another range.

LightningMan
March 21, 2009, 11:26 AM
Quote; Blakenzy I wonder why we don't see more snubbies in 9mm. Wouldn't it make for more compact pocket guns than .38spl, at least length wise?

+1 on that, it would indeed make a better CCW.

Radagast Quote;
Blakenzy Yes it would, but this would mean redesigning/engineering the revolvers to have a shorter window for the cylinder. The J & J Magnum frames are a stretch of the old I frame that the .38 S&W was chambered in many years ago. From the viewpoint of Ruger & S&W it is more viable to run with their standard frames, rather than introduce a new one.

I agree, but when Ruger came out with a totally new design with their LCR (polymer framed revolver) aimed at the CCW market, wouldn't it have made a small revolver even smaller still, without really giving up any loss of cartridge performance.

Radagast Quote; There have been short runs of 9mm chambered guns but they haven't built up any demand, possibly due to the need for moon clips.

Why can't the chambers for the revolver's cylinder headspace off the case mouth instead of the case's rim, like a .38 special? LM

wanderinwalker
March 21, 2009, 12:03 PM
BlindJustice,

You get me for trying to think and type too late for my brain! ;)

What I meant to say, and thought I had said, is exactly what you wrote: same powder, less space, more pressure. Same powder charge in .38 case = less pressure than in a 9mm case.

Back to your regularly scheduled posting.

BlindJustice
March 21, 2009, 12:15 PM
The 9mm is a 'rimless' cartridge whereas the.38 SPecail is a rimmed cartridge. "Rimless' is something of a misnomer since a 9mm x 19 does have a rim but it's the same diameter as the rear diameter of the case proper.
FYI - the .38 Super has a 'rebated' rim where the rim diamter is less than the diameter of the case itself. Very few cartridges have rebated rims, only one
I can think of besides the .38 SUper is the .284 Winchester.

To get back to the original .38 SPecial and it's limited pressure if kkept to
SAAMI spec.. 17,000 PSI for regular and 19000 PSI for +P when it was switched from 21.5 grains of Blackpowder to smokeless powder, it left a lot of unused empty space. Some handloaders will charge the sized & primed case with a charge, then insert wadding prior to seating and crimping the bullet. THis wadding will stabilize the powder to rest at the rear of the case
nearest the primer for consistent ignition. THis technique should be considered for any of the cartrdiges which started life as blackpowder ccharged cartridges.

R-

doubs43
March 21, 2009, 01:28 PM
ONly a very few of the M1917 Colt New Service revolvers were not counterbored for the correct chambering, none of the S&W N-frames were
made the way you incorrectly suggest. It doesn't have anything to do
with the strength of the .45 Auto RIm or how it headspaces via the rim and
not the mouth of the case like the .45 ACP. Doughboys were issued .45 ACP
in boxes where they had 8 half moon clips pre-loaded, two for the M1917 and 6 paired fit into thir bandolier that had three pockets

What does that have to do with the transition of cartrdiges from
blackpowder to smokeless ? Randall

First, I didn't specify WHICH of the 1917 revolvers were, or weren't "counter bored" so your snotty reply was unnecessary. Nor did I say ANYTHING about the strength of the rimmed case.... ONLY that they were made to make the half-moon clips unnecessary. I don't recall having mentioning HOW Doughboys were issued .45ACP revolver cartridges either. I know how they were issued as I've shot WW1 issue .45ACP cartridges in half moon clips straight from the long, narrow boxes. My father had quite a few of them at one time.

YOU first brought up the .45 Auto Rim cartridges so you tell me what they have to do with black powder.

As you seem bent on being technically correct, let me point out that the 9x19mm case is a TAPERED rimless case.

Furthermore, the .38 Super case is a SEMI-RIMMED case; NOT a rebated rim. A good example of a rebated rim case is the .41 Action Express, a cartridge that didn't stay around long. The early 1911 Colts made in .38 Super headspaced on the semi-rim of the case. Newer Colt .38 Super pistols headspace on the mouth of the case.

Not everyone on these boards is as knowledgeable as others and NO ONE knows everything about all guns. The information I posted was more for those who are learning than for those who have been around for awhile. It wasn't my intention to "correct" you or engage in a debate BUT I can be as civil as anyone OR I can also come back in the same condescending tone if that's how I'm addressed.

BlindJustice
March 21, 2009, 04:48 PM
My point was the .45 AR in my opinion has been incorrectly classified
by SAAMI to the pressure levels that the family of cartridges that started
off as blackpowder charged, but today are available with modern smokeless
powder from the major ammunition companies. Going into the detail of the
M1817 doub43 was started by you and it got off the point of comparing different cartrdges with a differing base design.

I'll leave it at that.

Randall

BlindJustice
March 21, 2009, 08:56 PM
Back to the O.P.'s subject,

THe Cartridge that was adopted by the US Military to approximate
the .45 Colt load of a 255 gr. Flat point, Round nose lead bullet
@ around 800 fps is of course the .45 Automatic Colt Pistol (ACP)
cartridge which fires a 230 gr. RN-FMJ at 830 fps as the original load
was as it was adopted. so, with the bigger bore cartridges, a similar
difference in cartridge length.

A 9mm LUger is to a .38 SPecial as
the .45 ACP is to the .45 Colt.

SInce a .40 cal. or 10MM didn't come along until
the early 80s, it's not quite the same comparing a .40
S&W to say the old 19th century .38-40 which is somethinng
of a misnomer since the bullet in a .38-40 is .401 same as
the .40 S&W or 10MM AUto bullets used in those cartridges.

R-

Radagast
March 21, 2009, 09:02 PM
LightningMan You are correct, a 9mm would have the same or better performance than a .38 special, but making a smaller frame would have precluded chambering the gun in .38 special (or .32 magnum in the future), which is the commercially successful snubby round. They obviously decided to go with what sells.

Re using 9mm that head spaces on the case mouth, A lot of 9mm hand loads I have seen over the years have such a crimp that there is no case mouth exposed to head space on. 9mm hand loads are also more likely to get a bulge in the middle when poorly loaded. Not every one uses factory ammo, so the manufacturers have to factor in the above possibilities. Moon clips mean that slightly out of spec rounds won't slip forward a little and prevent the firing pin from detonating them. Also ejection becomes a problem, you either need a stick to poke in each chamber or a variant of the fancy fingered extractor S&W used on the 547.

psyprofessor
March 22, 2009, 10:37 PM
So.. in plain English... the 9mm is as effective (in means of doing damage to the BG) or slightly more so than the 38 spl. + P....

Did I get that right???

Hostile Amish
March 22, 2009, 10:48 PM
9mm has same performance as .38 Spcl except .38 Spcl operates at about 3000 more psi.

BlindJustice
March 22, 2009, 11:09 PM
Not sure what the last statement means

SAAMI specs.
.38 Special = 17,000 PSI
.38 SPecial +P = 19,000 PSI
+P+ means it's behond +P & SAAMI recommended pressures

9mm Luger = 35,000 PSI or near that
and +P must be at least 2K above that.

It also depends on barrel length, of course.

Randall

Radagast
March 23, 2009, 02:40 AM
Psyprofessor:
9mm and .38 special are essentially the same diameter, bullet weights can be similar, eg: 110 grain vs 115 grain, 125 grain vs 130 grain, 147 grain vs 158 grain) 9mm is usually faster and as a result has more energy, 38 special bullet construction in the early days was more likely to result in an expanding bullet than the 9mm, this is less of an issue with modern designs.

Short summary: 9mm wounding capability with current ammunition is probably as good as or better than .38 special for comparable loadings.

logical
March 23, 2009, 11:04 AM
Short summary: 9mm wounding capability with current ammunition is probably as good as or better than .38 special for comparable loadings.

9mm has same performance as .38 Spcl except .38 Spcl operates at about 3000 more psi.

If you look at comparable numbers, I think you'll actually see that even standard pressure 9mm has considerably more energy than .38+P and 9mm +P is in a whole other league than even .38+P. I don't think anyone considers standard .38 a viable defensive round anymore do they?

Speer Gold Dot:

124 grain 9mm standard 364 ft lbs energy at muxzzle
124 grain 9mm +P 410 ft lbs
125 grain .38 +P 248 ft lbs
125 grain .357 584 ft lbs

It's even more dramatic in the "Short barrel" versions.

ArmedBear
March 23, 2009, 11:12 AM
Muzzle energy grossly overstates the difference between loadings.

List the velocities, and at least there will be some semblance of truth the the comparisons.

logical
March 23, 2009, 11:22 AM
Muzzle energy grossly overstates the difference between loadings.

List the velocities, and at least there will be some semblance of truth the the comparisons.

With the bullet weights I listed all being within one grain, I think it's valid. If you want to do the math or look at the Speer site you can list the velocities but obviously the rank will stay the same. If you want to make a point, I think the burden is on you to post some numbers...or something. How exactly does muzzle energy grossly distort comparrisons when the rounds are the same bullet weight?

Here's the velocities: 9mm:1150, 9mm+P:1220, .38+P:945, .357:1450

The square root of a little number is still smaller than the square root of a big number, and I would argue that energy is a more reasonable indicator of relative effectiveness than velocity.

ArmedBear
March 23, 2009, 11:33 AM
It's not the rank, it's the slope that's unrealistic.

A quick look at Cor-Bon's site shows how.

9mm+P 125 grains 1250 fps 434 ft-lbs.
.38Sp+P 125 grains 950 fps 251 ft-lbs. (snubbie load)

That makes it appear like the 9mm is 70% more effective because it's going 30% faster. And that's not true. ME grossly overstates the difference in the real world, as I said.

Is the 9mm in question a more powerful round than the snubbie .38 Special? Of course.

Is it 70% more effective? No way, no how.

How can I say this? Hunting.

I would argue that energy is a more reasonable indicator of relative effectiveness than velocity.


Sure. The only problem is, you'd be wrong.:D

Momentum is a more reasonable indicator, and since momentum = mass * velocity, if mass is held constant as in our posts above, that means that velocity is a perfectly adequate stand-in.

Energy is a great way for marketers to make a small increase in powder charge look like a big deal, or to make a small bullet look as effective as a big one, by pushing it marginally faster. It's not the best number to look at when your life depends on it.

(Small, high-velocity rounds can be VERY effective, per Roy Weatherby, but we're talking about bullets going mach 3, not a little bit on one side or another of 1000 fps.)

logical
March 23, 2009, 12:10 PM
I'm losing the energy to keep the momentum of this discussion going...and doing so at a significant velocity. It isn't an arguement, it's a discussion.

Kleanbore
March 23, 2009, 12:57 PM
Momentum is a more reasonable indicator[than kinetic energy], and since momentum = mass * velocity, if mass is held constant as in our posts above, that means that velocity is a perfectly adequate stand-in.

Can't agree with that.

Momentum is conserved in an inelastic collision such as that of a bullet with flesh and bone---but so what? That simply means that the total momentum of the combined bullet and target mass is the same as that of the bullet prior to penetration.

Big deal. Due to the overwhelming ratio of the mass of the target to that of the bullet, the velocity imparted to the target (i.e., the effect of momentum) is insignificant and virtually meaningless. Comparative momentum therefore has little to do with comparative bullet effectiveness.

However, energy does. Take a look at the velocities of the .38 Long Colt, .38 Smith and Wesson Special, .357 Remington Magnum, and .357 Remington Maximum with bullets of the same weight. Which is a better indicator of effectiveness, the ratios of the velocities or those of the squares of the velocities, assuming that the bullets do not pass through the targets? I suggest that the improvement of the .38 Spl. over the service cartridge is far greater than the ratio of the velocities would suggest.

Seventy years ago the .300 Holland and Holland Magnum was the odds-on favorite over the .303 and .30-'06 with the same bullet weight for larger soft-skinned game, with a much bigger advantage than the 7% increase in momentum would indicate.

The reason for the answer is that in an inelastic collision, the much higher kinetic energy of the faster bullet is dissipated into upsetting the fluid content of the target, injuring neurological and other systems.

The physics are entirely scalable, so in theory the same relationships apply at one-third the velocities here. In practice, however, penetration and wound channel will be more pertinent in a medium-power pistol comparison, so in the discussion at hand (9MM Luger vs. .38 S&W Special) they are more relevant.

That does not elevate momentum to the status of being a meaningful measure of effectiveness, however, nor does it indicate that kinetic energy, which has been the parameter of choice among experts for more than a century, is not a much better measure.

SaxonPig
March 23, 2009, 01:05 PM
If limited to factory ammo the 9mm has the performance edge. If hand loading the 38 can come close to the 9mm but the 9 still operates at a higher pressure so will always have an advantage.

If you don't mind exceeding industry standards for the 38 in a good quality gun you can match 9mm performance.

Winchester and Federal load a +P 9mm round with a 115 JHP that clocks right around 1250 from my gun. I load 125s in the 38 Special to 1100-1150 for my carry 38s. I have gone to 1200 without any bad things happening but I backed off a tad just for peace of mind. I reckon a 125 at 1200 .38 just about equals the 115 at 1250 9mm in terms of real effectiveness. At 1150 the 38 gives up just bit but probably would not be noticed.

ArmedBear
March 23, 2009, 01:17 PM
Momentum is conserved in an inelastic collision such as that of a bullet with flesh and bone---but so what?

When momentum is conserved, velocity is conserved, by definition.

If velocity is not conserved, the bullet slows down, by definition.

As the bullet slows down, it eventually stops.

When it is no longer moving, it doesn't do anything any more.

Momentum determines just far the bullet can go -- in the target, not in the air -- before it quits having any effect.

Energy does not.

Momentum is the reason a .45-70 with less than the magic 1000 ft-lbs that small-caliber hunters consider a requirement for deer, can drop a North American Bison.

It would be pretty hard to sell smaller rounds for defense, if momentum was listed instead of energy.

From Elmer Keith: "Martin pulled his .38 and put all six shots in the man's chest. Then the man threw the revolver at Martin... I told Martin, "Now if you'd used a heavy gun, you could have shot him in the shoulder and put him out with one shot and probably not had to kill him." (Martin was a local cop who had been showing off his new .38 Special to Keith.)

WRT the scalability of hydrostatic shock, you're dealing the the ability of a biological organism to compensate for sudden pressure changes. There's nothing linear about that, any more than there is about a balloon's ability to withstand pressure. At some pressure, it pops. Below that point, it doesn't pop. It's most assuredly not "scalable."

.300 H&H, like the .300 Win Mag today, was popular because you could put a reasonable powder charge behind a heavy bullet, i.e. more momentum.

logical
March 23, 2009, 01:41 PM
When momentum is conserved, velocity is conserved, by definition.No, it is not. Momentum can be conserved but transferred. It results in a velocity increase of various values to various parts of he who has been shot. Seriously...did you actually invoke Elmer Keith?????????????

ArmedBear
March 23, 2009, 01:48 PM
I understand the physics of what you're saying, but the amount of velocity that can be transferred to the target before the bullet stops moving is proportional momentum, not energy, so you are arguing against yourself.

WRT Keith: The difference between you and Elmer Keith is that he cleaned a lot of large game with many different types of rounds and saw what the bullets did AFTER THEY HIT.

Your arguments make that clear.

That's all I can say.

Hopefully, neither one of us will ever have to find out, firsthand, just how effective that 410 ft-lb. 9mm load really is. Pointing a .22 at a home invader is probably just as effective as pointing a .44 Magnum -- the difference only comes into play if he's a committed attacker.

After seeing a bit of what slow but heavy bullets do on really large game, two things happened. I stuck my 9mm in the safe and bought a .45, and I gained a lot of respect for Elmer Keith's opinions (of course he also used a .300 H&H Magnum, and similar guns, BTW).

Too much of the ballistic data we see is designed to sell us stuff, IMO.

logical
March 23, 2009, 02:03 PM
I am not arguing against myself or you. I didn't say anything in my last post about energy. It was a comment, about your comment on momentum.

Elmer shot a lot of things, I studied physics....both have merit in this discussion.

Your point is that enery numbers may distort the relative effectiveness of a given round vs another. OK, I suppose if a person is unable to understand anything beyond a simple linear relationship that's true. I understand it isn't linear. I never said twice the energy means twice the effectiveness.

Do you somehow think you can only be "right" if everyone else is "wrong"?

Kleanbore
March 23, 2009, 02:39 PM
When momentum is conserved, velocity is conserved, by definition.


No, not after the collision. The total momentum of the two bodies after penetration is equal to that of the bullet upon impact. That means that with the bullet in it, the target has had imparted to it a change in velocity. And that change is meaningless. And so, therefore, is the momentum, which, together with the mass of the target and the comparatively insignificant mass of the bullet, determines the velocity of the combined mass.

As the bullet slows down, it eventually stops. When it is no longer moving, it doesn't do anything any more.

OK....

Momentum determines just far the bullet can go -- in the target, not in the air -- before it quits having any effect. Energy does not.

Do you believe that the increase in stopping distance of a car under maximum braking is proportional to the increase in speed, or to the increase in the square of the speed? Think about it.

Momentum is the reason a .45-70 with less than the magic 1000 ft-lbs that small-caliber hunters consider a requirement for deer, can drop a North American Bison.

Is it really?

WRT the scalability of hydrostatic shock, you're dealing the the ability of a biological organism to compensate for sudden pressure changes. There's nothing linear about that, any more than there is about a balloon's ability to withstand pressure. At some pressure, it pops. Below that point, it doesn't pop. It's most assuredly not "scalable."

Didn't say it was linear, but it certainly is scalable, unless the target explodes. May not be very meaningful at the low end of the envelope, but it is scalable.


.300 H&H, like the .300 Win Mag today, was popular because you could put a reasonable powder charge behind a heavy bullet, i.e. more momentum.

As I recall, a 180 grain bullet was the preferred bullet for soft-skinned game for either cartridge.

WRT Keith: The difference between you and Elmer Keith is that he cleaned a lot of large game with many different types of rounds and saw what the bullets did AFTER THEY HIT.

So did Roy Weatherby, as I recall.

I understand the physics of what you're saying, but the amount of velocity that can be transferred to the target before the bullet stops moving is proportional momentum, not energy...

And you somehow wish to contend that the velocity imparted to a bison when it is struck by a bullet is meaningful in the scheme of things? Do the math, and I think you'll find that a .45-70 405 hitting at 1,400 FPS will start a 2,200 pound bison moving at about four tenths of an inch per second...

Hit it with a well-constructed bullet of the same weight moving at over 2,800 FPS and you'll see an imperceptible increase in the velocity of the animal, but I'll wager it will drop a lot more quickly.

Too much of the ballistic data we see is designed to sell us stuff, IMO.

Hard to argue with that!

BlindJustice
March 23, 2009, 02:48 PM
Whoever put the quote or claim in that most experts rely on kinetic energy as a baseline of effectiveness for the last 100 years - well not
according to Hatchers real world tests, or Jack Lott's observations of various
rifles/cartrdige/bullet weight performance in Africa as well as Jeff Cooper
didn't he have a rule of thumb formula?

.45-70 is still carried by a lot of guides in Alaska

R-

ArmedBear
March 23, 2009, 03:07 PM
Do the math, and I think you'll find that a .45-70 405 hitting at 1,400 FPS will start a 2,200 pound bison moving at about four tenths of an inch per second...

Hit it with a well-constructed bullet of the same weight moving at over 2,800 FPS and you'll see an imperceptible increase in the velocity of the animal, but I'll wager it will drop a lot more quickly.



Have you ever done it?

I have. One shot, DRT. Might have come in a bit under a ton, though.

But not with a pathetic little bullet like a 405, though it wasn't going so fast, either.:D Black powder 528 grain hardcast lead.

How many inches you nudge the bison has NOTHING WHATSOEVER to do with dropping it, unless you are talking about clubbing it to death (not recommended).

That's what people have so utterly wrong about bullet energy. You're not trying to nudge something to death.

But what the hell. 9mm vs. .38 is like Pinto vs. Vega. I've got a .38 Special Airweight J-frame, because it's light, small and simple. But I consciously sacrifice having a really good round, in return for light, small and simple. I frankly don't expect any one-shot stops with it. Ditto for 9mm. There's really no good reason to choose either round in 2009 if it's in a full-size gun (or you deliberately want to shoot a lower-powered round because of overpenetration issues -- and then you'd best understand that you are giving up effectiveness by choice).

sm
March 23, 2009, 03:11 PM
But what the hell. 9mm vs. .38 is like Pinto vs. Vega.

You just dated yourself for sure!

*grin*

ArmedBear
March 23, 2009, 03:16 PM
So did Roy Weatherby, as I recall.


See my post above, but I'll elaborate further.

Since you concede that the scalability is highly nonlinear (vaguely an oxymoron, but I'll take the dubious wording at face value), and that things change when organs explode, Roy Weatherby's experiments can coexist with .45-70 bison hunting without any contradiction.

Roy Weatherby's successful rounds come out of the muzzle at Mach 3 or higher. His one-shot drops of big game with tiny bullets at very high velocities were affected by creating a shockwave strong enough to explode the animal's vascular system. That was my point from the start: the handgun rounds in question do not go fast enough to make this relevant.

Yes, Weatherby's method works. But 9mm, .38, .357, .44, .40, .45, etc. do not operate anywhere near that velocity range.

ArmedBear
March 23, 2009, 03:17 PM
You just dated yourself for sure!

*grin*


...or gave myself away as someone who has (at least on occasion) gone to watch local Pony Stock racing...:D

Ugh!

logical
March 23, 2009, 03:19 PM
If I am attacked by a bison, I will keep all of this in mind.

ArmedBear
March 23, 2009, 03:24 PM
You probably won't be attacked by bison in Michigan.

However, you might be attacked by someone wearing a thick leather jacket...

And you'll be using a round at what hunters consider "black poweder velocity" to defend yourself. That's probably the best real-world data you can find, since we don't live in a society where we routinely shoot people.

logical
March 23, 2009, 03:37 PM
since we don't live in a society where we routinely shoot peopleyou haven't been to Detroit lately have you

ArmedBear
March 23, 2009, 03:57 PM
Nah.

My wife went to school at U of M and has relatives in that area.

I've never even been to Detroit, but nothing she's told me about it has made me too eager to vacation there -- except the novelty of seeing places even worse than LA in the 70s when I was a kid in the area.:D

Now a lot of the rest of Michigan sounds really nice, though.

Kleanbore
March 23, 2009, 04:22 PM
How many inches you nudge the bison has NOTHING WHATSOEVER to do with dropping it, unless you are talking about clubbing it to death (not recommended). That's what people have so utterly wrong about bullet energy. You're not trying to nudge something to death.

That would be entirely correct if you were to substitute the word momentum for energy (not that very many people have hung their hats on momentum as a measure of effectiveness), and it would then state my point very well indeed.

Since you concede that the scalability is highly nonlinear (vaguely an oxymoron, but I'll take the dubious wording at face value), and that things change when organs explode, Roy Weatherby's experiments can coexist with .45-70 bison hunting without any contradiction.

It ain't a concession that the scalability is highly nonlinear, it's the crux of the matter. Momentum is directly proportional to velocity (a linear relationship). Kinetic energy is proportional to the square of the velocity (an exponential relationship). I was not implying that the physics is not scaleable when organs explode; I was referring to the possibility that the game might disintegrate. Not sure that's relevant.

Same thing with aerodynamic drag: within a fluid, it's going to take a lot more to stop a bullet going 1,200 FPS than one of the same weight going 900. How much effect the shock might have is open to question, but the penetration will be a lot greater (same as stopping the faster car--distance has to do with the kinetic energy), and assuming the bullet does not pass through the target, it should therefore be more effective. It's also the energy that will drive expansion.

Roy Weatherby's successful rounds come out of the muzzle at Mach 3 or higher. His one-shot drops of big game with tiny bullets at very high velocities were affected by creating a shockwave strong enough to explode the animal's vascular system.

While the energy vs. bullet weight argument often brings up the experiences of Weatherby and Keith (or Lazzeroni and Lott, for younger people who maycare), let's not forget that the effectiveness of higher velocity rifle rounds was noted long before Roy ever started reaming chambers. consider the .30-30 vs. the .32-40; the .30-40 and later .30-'06 vs the .30-30 or .303 Savage; and the .300 H&H. At what point the impact begins to explode the vascular system vs. simply hindering its function (and that of the neurological system) through shock, I don't know. It as long been noted that the effectiveness of a high powered rifle, unlike that of an arrow, accrues from energy in addition to laceration, and that doesn't require a bullet that travels at 3,300 FPS.

That was my point from the start: the handgun rounds in question do not go fast enough to make this relevant.

Actually, I though your point was that one should base conclusions on momentum.

However, as one who carries a .38 Special, I am not concerned about the higher energy of a 9mm, except to the extent it may result in over penetration and thus become a liability.

ArmedBear
March 23, 2009, 04:34 PM
That would be entirely correct if you were to substitute the word momentum for energy (not that very many people have hung their hats on momentum as a measure of effectiveness), and it would then state my point very well indeed.


Not true. Momentum is a pretty good indicator of how far a bullet will travel inside a target, and what sorts of obstacles it will be able to break through before it stops. It is not a complete measure of "effectiveness"; it's just a more meaningful measure of one component of effectiveness than energy is.

It as long been noted that the effectiveness of a high powered rifle, unlike that of an arrow, accrues from energy in addition to laceration, and that doesn't require a bullet that travels at 3,300 FPS.


If you read old accounts of hunting, you will read about many shots commonly being used to bring down one animal with the rounds you listed.

Roy Weatherby showed how he could drop big game, DRT, with a single little bullet going really fast.

The difference comes from Weatherby's VERY high velocities, and little else.

But even if you're using .30-06 as an example, a deer load is something like 150 grains going 2910 at the muzzle -- still well above the range of numbers we're talking about.

Actually, I though your point was that one should base conclusions on momentum.


Only instead of energy, at handgun velocities.

I was not implying that the physics is not scaleable when organs explode; I was referring to the possibility that the game might disintegrate. Not sure that's relevant.

It is relevant. When organs explode (or game explodes), that takes a good deal of energy.

This will work, as Roy Weatherby demonstrated.

The energy required is far outside the parameters we're discussing -- because a mammal like a man or a deer can withstand a shockwave up to a certain threshold which is far above the energy of the hottest 9mm available.

Let me expand;) on "nonlinear": I mean stretch-stretch-stretch doesn't drop an animal. Stretch-stretch-stretch-POP! drops an animal in Roy Weatherby's world.:)

My point is that there's a very important dichotomy.

Below a particular threshold of bullet velocity (and energy), energy means very little. Bullet momentum means more, because it is a better indicator of the bullet's behavior on target.

Above a particular threshold, that does change. But we're not anywhere near that threshold.

Kleanbore
March 23, 2009, 05:57 PM
Momentum is a pretty good indicator of how far a bullet will travel inside a target,

Actually, I believe that with a little study, you will come to the conclusion that, in an ideal fluid (probably including gelatin), energy is a far better indicator, given the same bullet construction, design, and sectional density. Simple physics. Essentially the same as drag and dynamic braking.

...and what sorts of obstacles it will be able to break through before it stops.

At that point we depart from simple physics. It may well be (and it stands to reason to me, but you have the experience to judge) that a heavier bullet moving more slowly, with the same energy but with higher momentum, will be able to go through bones more effectively. I don't know, but the guys with the big guns in Africa might.

When organs explode (or game explodes), that takes a good deal of energy.

Good point.

Below a particular threshold of bullet velocity (and energy), energy means very little. Bullet momentum means more, because it is a better indicator of the bullet's behavior on target.

Second point first: One more time, unless the issue is penetrating bone, the only way momentum enters into the picture (other than in terms of recoil) is in how much velocity is imparted to the target--how much the target is "nudged," in your words--and I believe that is meaningless, and you've said so too.

Regarding energy: Assuming the same sectional density and bullet construction, energy will drive penetration, except possibly in the case of bone. As I understand things, penetration, and wound channel diameter will be critical.

...a mammal like a man or a deer can withstand a shockwave up to a certain threshold which is far above the energy of the hottest 9mm available.

Could be, and it makes sense. Is there empirical data to prove that the shock is not debilitating? You sure don't have to explode any organs to do damage.

You can knock a man out with a blow to the ribcage without breaking anything. How much energy is involved? Might the effect of an expanding bullet hitting near an organ or nerve be temporarily damaging?

I won't argue the point when it comes to a 9MM, but I really don't know, and I do think that a hot .357 from a long barrel is probably a different story.

By the way, I retired my 9MM some time ago, because it will only function reliably with ball ammunition. Neither the energy nor momentum in a bullet that has passed through the target is of any use to me.

doubs43
March 23, 2009, 08:47 PM
You can knock a man out with a blow to the ribcage without breaking anything. How much energy is involved? Might the effect of an expanding bullet hitting near an organ or nerve be temporarily damaging?

That's an interesting point. "Wild Bill" Hickock favored the 1851 Colt Navy revolver in .36 caliber I believe. He's said to have claimed that he always tried to hit a man as close to his navel as possible because it seemed to take the fight out of him very quickly. A man that calculating and cool would be a dangerous man to face.

ArmedBear
March 24, 2009, 09:35 AM
Yeah, but Wild Bill also died at 36 as I recall.:)

woad_yurt
March 24, 2009, 10:19 AM
If one has a mass (like a bullet) moving along at a certain speed and one then doubles that velocity, the kinetic energy (ft lbs) is quadrupled as a result.

Check out the following example:
A 9MM 125 gr bullet moving at 1175 fps has 383.3 ft lbs of kinetic energy at the muzzle while a .38 SPL 158 gr bullet going 900 fps developes only 284.24 ft lbs.

If only I there was a Model 10 chambered for 9MM....

Kleanbore
March 24, 2009, 11:02 AM
The divergence between theoretical physics ("ignoring the effect of...", "assuming that the target behaves like a fluid," etc.) and the real world has been bothering me.

Forget everything I've said on this thread, print the following, and set aside some time.

http://www.rathcoombe.net/sci-tech/ballistics/wounding.html#introduction

As is so often said ungrammatically in restaurants, enjoy!

woad_yurt
March 24, 2009, 11:49 AM
Those figures I posted don't ignore anything. In probable self-defense situations (at short, short range,) bullet drop, air drag and such are all almost too small to measure, much less worry about.

This post was about 9MM vs. .38 SPL. Is it still?

ArmedBear
March 24, 2009, 11:58 AM
The divergence between theoretical physics ("ignoring the effect of...", "assuming that the target behaves like a fluid," etc.) and the real world has been bothering me.

I'm with you there.

If you look at ballistic gel tests, a light .380 looks a lot like a heavy .45ACP. Yeah, they look a little different, but not MUCH different.

Nobody who has hunted with handguns or other low-velocity firearms (not to mention a good number of dead US soldiers buried in the Philippines) would equate this appearance with reality.

Kleanbore
March 24, 2009, 12:31 PM
Those figures I posted don't ignore anything. In probable self-defense situations (at short, short range,) bullet drop, air drag and such are all almost too small to measure, much less worry about.

True. I was referring to the discussion of the effects of energy on effectiveness after the bullet enters the target.

This post was about 9MM vs. .38 SPL. Is it still?

Yeah, but the discussion about terminal ballistics would apply to other comparisons.

ArmedBear
March 24, 2009, 12:36 PM
The question I raised was, simply, "Does pushing a 125 grain .35" bullet a couple hundred FPS faster REALLY make it that much more effective?"

That's a terminal ballistics question if there ever was one.:)

oneounceload
March 24, 2009, 12:45 PM
If only I there was a Model 10 chambered for 9MM....

There is, it's called the 547 - a K-frame 6 shot 9mm that does not need moon clips; came in 3 and 4 inch versions - on my wish list

woad_yurt
March 24, 2009, 03:12 PM
I should've said "an affordable Model 10...."

To Armedbear's question:
A 125 gr bullet at 900 fps develops 224.88 ft lbs of muzzle energy while the same bullet at 1100 fps gives one 335.93 ft lbs of muzzle energy.

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