Bullet Caliber Comparison

gdeal

Bullet Caliber Comparison
Why is a .38 considered so lame and a .40 considered half way decent?
The difference is only .02
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If you are concerned with comparing these on the issue of incapacitation of a human threat; then you are concerned about which one consistently causes a greater volume of tissue damage which then causes more hemorrhaging, loss of circulatory pressure, and incapacitation.

It takes energy to crush tissue. It requires contact by the bullet to crush tissue. These two factors make deforming bullets which penetrate to a reasonable depth (12" - 18" <-- subject of much discussion) without upset (tumbling); the desired defensive handgun bullet design. Obviously the larger the area of the bullet in contact with tissue, the larger the volume of tissue crushed for any given depth of penetration, and the greater the bleeding, and the faster the incapacitation.

Volume of a Cylinder
V = pi r2 h Pi = 3.14159

r of 38spl = .357/2 = 0.1785”
r of .40 S&W = .40/2 = 0.20”

V per inch of penetration of .38spl (w/o expansion) = 0.56 cu. inch

V per inch of penetration of .40S&W (w/o expansion) = 0.628 cu. inch

The volume is about 12% greater for the .40S&W

Variables to be considered in how much tissue is crushed are amount of expansion of hollow point bullets, depth of penetration, and tumbling.

If a bullet expands to .70" but then tumbles and penetrates with its smallest cross-section as the leading edge contacting tissue then the crush volume is lessened.

Assuming two bullets of the same initial energy and dimensions fired from the same gun into a test medium. If one bullet expands quickly, does not tumble and crushes tissue with its full frontal area of .70", then the energy per unit of penetration used will be greater than a bullet of the same initial size and energy that presents a .45" frontal area. This larger frontal area will result in a shallower penetration; and theoretically, the same volume of tissue is crushed.

There is a great amount of discussion about what is the "best" range of penetration for a defensive handgun bullet. There are existing threads which discuss this issue and the Search feature can find them for you.
 
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So they went to the 10mm which is .40cal wide and almost as hot as the 357. They ran into two problems: some agents didn't like the recoil and the early S&W guns started literally cracking. So they loaded the 10mm with less powder, ran reduced power recoil springs in the same guns and solved both problems, but that left them with guns that were oversize for the horsepower used. Somebody at S&W realized you could shorten the 10mm to 9mm shell length and use the new shorter 10mm (loaded the same as the "10mm lite" loads) in smaller, handier guns that better fit the hands of smaller and/or female agents. And thus was born the 40S&W, basically as a result (over several steps) of the Miami shootout.
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Very interesting.
 
Guys,

We agree that the "energy over every other factor" mentality can be taken too far, and I think that level of diminished returns has been hit with the FN 5-7 and some of the very fast 110gr-and-below 357 loads, and a few others.

However, the 125gr 357 loads have shown themselves to have enough mass, and a proven track record and then some. One factor I didn't mention: bullet construction. Doubletap and Buffalo Bore both use Speer Gold Dot projectiles for this application, and the Gold Dot works great at high speed because the copper jacket is really just a heavy electroplate over the lead core. That means the copper is strongly bonded to the lead and acts to prevent the nose cavity flying apart on high speed hits.

If you took a classic 125gr slug like the Remington semi-jacketed hollowpoint (basically a first-generation jacketed hollowpoint, late 1970s tech) and ran it 200+ feet per second faster than where Remmie runs it, it would fall apart. Gold Dots won't.

Upshot: since the 125gr slug doing 1,450ish has a proven track record, bumping it up past 1,600fps isn't going to harm the concept so long as the slug holds up. The Gold Dot will. And I think in some circumstances, with big energy "adding to" the wounding going on instead of trying to be "everything", big energy can help so long as you can deal with the resulting recoil.

A 43oz 357Mag revolver with grips I customized to my hands and shooting style lets me control those monsters even shooting one-handed.
 
I think Jim is missing one point: Energy is important, but for a different reason.

When the bullet hits the human body, at high velocity, it can blow right through the target when the velocity is too low, or, the bullet is too strongly constructed. Skin is an important factor. It's pretty tough. Good example is the offside skin is equal to about 5-6" of gello penetration. So, with the high
speed, the bullet opens upon hitting the skin, making for maximum bullet expansion, in the shortest possible time, and, leaving a good sized hole.

The higher velocity can actually decrease penetration, by causing earlier, larger expansion.

For reference, Hawk bullets wants at least 1400 fps, if possible, with their .025" Hollow points, for that reason. Double tap has also used Gold Dots as Jim mentioned, and, they expand very well:

DoubleTap 9mm+P
115gr. Gold Dot JHP @ 1415fps - 12.00" / .70"
124gr. Gold Dot JHP @ 1310fps - 13.25" / .70"
147gr. Gold Dot JHP @ 1125fps - 14.00" / .66"

DoubleTap .40 S&W Penetration / expansion
135gr. Nosler JHP @ 1375fps - 12.10" / .72"
155gr Gold Dot JHP @ 1275fps - 13.00" / .76"
165gr Gold Dot JHP @ 1200fps - 14.0" / .70"
180gr Gold Dot JHP @ 1100fps - 14.75" / .68"
200gr XTP @ 1050fps - 17.75" / .59"


DoubleTap .357 Sig
115gr Gold Dot JHP @ 1550fps - 12.25" / .71"
125gr Gold Dot JHP @ 1450fps - 14.5" / .66"
147gr Gold Dot JHP @ 1250fps - 14.75" / .73"

DoubleTap .357 Magnum
125gr. Gold Dot JHP @ 1600fps - 12.75" / .69"
158gr. Gold Dot JHP @ 1400fps - 19.0" .56"

DoubleTap 10mm
135gr JHP @ 1600fps - 11.0" / .70" frag nasty
155gr Gold Dot JHP @ 1475fps - 13.5" / .88"
165gr Gold Dot JHP @ 1400fps - 14.25" / 1.02"
165gr Golden Saber JHP @ 1425fps - 14.75" / .82"
180gr Golden Saber JHP @ 1330fps - 16.0" / .85"
180gr XTP @ 1350fps – 17.25” / .77”
180gr Gold Dot JHP @ 1300fps - 15.25" / .96"
200gr XTP @ 1250fps - 19.5" / .72"
230gr Equalizer @ 1040fps - 11.0" and 17.0" / .62" and .40"

DoubleTap .45ACP
185gr Gold Dot JHP @ 1225fps - 12.75" / .82"
200gr Gold Dot JHP @ 1125fps - 14.25" / .88"
230gr Gold Dot JHP @ 1010fps - 15.25" / .95"
 
That's a GREAT site, but, for a different reason then most think. By looking at what length barrel the round hits peak velocity in, you have a REAL good idea if the round is tailored to your carry gun.

Also, you can take the length of your gun, compare it to the peak velocity of the round, and, figure out if the powder is fast or slow, and, again, is tailored to your application.

The higher the percentage of lost velocity from your length barrel, the less likely that's the best round for your gun...
 
"When the ammo companies started switching to what is known as outside lubricated bullets, the type we see today"


Correction.

Heeled bullets, the kind that are now only seen in the .22 Long Rifle, are outside lubricated (heeled) bullets.

This means that the lubrication was applied to the bullet and was exposed to all outside influences, like pocket lint, dirt, etc.

Inside lubricated bullets, the kind commonly used today, have the lubrication (which is normally packed in "grease grooves") covered by the case.

Heeled bullets were originally adopted as one of the means of easily dealing with the many black powder cap and ball revolvers that were being converted to cartridge use after the Civil War.

The heeled bullet was necessary to get a bullet that would fit the bore of the gun without having to bore the cylinder larger to accommodate the larger diameter case required by inside lubricated bullets.

In the 1880s and 1890s companies began to abandon the heeled bullet because of the issues with lubrication and also because it's easier to manufacture ammo that doesn't have a heeled bullet.

To accommodate the many older revolvers that would otherwise be rendered obsolete by the new smaller diameter bullets, manufacturers used very soft lead bullets with large hollows in the base, leaving a 'skirt' at the base of the bullet.

On firing, the skirt would expand into the rifling and at least give passable accuracy. Or, at least that was the plan, which didn't always work.
 
I just really dont understand why? Why they even bothered developing the 40 S&W round when they had the .45 acp which is know to do everything the .40 S&W can do, only just a little bit better with out the harsh recoil?
 
Why have 99.9% of the rounds been developed that have been developed?

There are three, four at the most, that will get 99% of the people through 100% of their everyday shooting activities.
 
The 40 is actually a pretty good compromise round: it allows decent power yet a double-stack magazine doesn't result in a King Kong-sized grip.
 
history

But why do they call it a .38 then if it is really closer to a .36 ?
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I dig history.
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The explanations about the nomenclature of the .38(.357) are the best that I've seen on an Internet forum. The whole practice of naming cartridges is fascinating if frequently illogical.
Examples of this are many, in addition to the .38.
A few are:
The 9mm Luger is .355" dia. but the 9mm Makarov is .362-.365" dia.
The .44 Special and .44 Magnum are .429 dia.
The .454 Casull is .452.
And then there's rifle cartridges. The .219s are actually .224s. The 256 Win is .257. The 240 Weatherby is .243. And on and on.
Pete
 
Since no one makes a 45 Super or 45 ACP plus P, double stack, 10 round gun, with decent magazines, for a reasonable price, in the People's Republic of California that is approved by our Gun Dictator, the Glock 29 is pretty much as many rounds, with as much punch, as you can get in a Kalifornia gun.
 
Mike Irwin-

You are correct, and thanks for straightening that out. It is what I meant, but not what I typed. My bad. I got my terminology backwards.
 
Why they even bothered developing the 40 S&W round when they had the .45 acp which is know to do everything the .40 S&W can do, only just a little bit better with out the harsh recoil?
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Because the .40 fits in the same size handgun as the 9mm. As mentioned one objection to the 10mm was that folks were giving up sleek lightweight 9mms for heavier, larger 10mms. For gun manufacturers, S&W, Glock, Springfield, etc., the .40 meant they could use the same size frames as they were using for their 9mm guns. Round count in a mag is also higher with the .40 than the .45 in a piece of the same size.

tipoc
 
Good point. Also, in free states, the large capacity magazines are an advantage, and, lightweight guns for police are important, since back problems from the cop belt end up in a bunch of money spent, through insurance.
 
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