Is there really a BULLET difference between the .38 and the .357, 9mm, ...

F

FUD

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Haven't asked a "stupid question of the day" in a while so here goes ... Looking at the actual BULLET piece of a .38 special and a .357magnun, there doesn't appear to be much/any difference between the two -- the only difference comes into the picture with the higher pressure/velocity of the .357mag but if the .357mag was handloaded to the same pressure as the .38 special, wouldn't the bullets fired from the two have the exact same effect? Can the same thing be said about the 9mm, .357Sig, .38Super, etc.? After all, they're all firing a .355" bullet. If all of these rounds were handloaded to the same pressure, wouldn't the bullets fired from all of them have the same effect or would some still be superior to others?
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FUD
 
You got it, FUD. The reason that velocity plays such a role is that energy (the capacity to do work) increases exponentially with increased velocity. Double the weight of the projectile and keep rate the same, you double the energy. Double the velocity and keep weight the same, you quadruple the energy. A 125 grain Gold Dot hollowpoint at 1000 fps fired from a 38, 357, 38 Super and 9mm are the same thing. The same bullet fired from a mag at 1500 fps will be capable of *alot* more "work". Physicists please chime in!

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semper ubi sub ubi
 
Yup, you got it right. The formula for kinetic energy of an object undergoing linear motion is:

KE=.5 x M x (V x V)

Where:

KE = Kinetic energy, usually in Joules or foot-pounds
M = Mass
V = velocity

Go to http://customguns.tripod.com/calcnrg.html if you want to calculate the results.

By doing the math, it easy to ee that since the energy inceases with the *square* of the velocity, the energy goes up dramatically with an increase in velocity. For example, let us compare identical bullets going 1000 fps versus 1250 fps.

Formula used:
Energy = .5 * weight * velocity^2 / 7000 / 32.175

Where weight is in grains, and velocity is in feet/second.

7000 is grains per pound, and 32.175 is acceleration due to gravity.

It can be re-written:
Energy = weight * velocity^2 / 450450

Energy of a 125 grain projectile at 1000 fps: 277.5 ft-lbs
Energy of same at 1250 fps: 433.6 ft-lbs.

Ae you can see, a 25% velocity increase increased energy by 56.25%!
 
A minor correction - .38 Spcl and .357 Mag use bullets .357 or a little more in diameter, but 9mm and 38 Super use the .355 bullets you mentioned. Otherwise, I think the observations about bullet effect are correct.
 
If you're talking about actual bullet construction, that depends.

Some bullets, such as Remington's Golden Sabre line, are optimized to work within certain velocity ranges.

IOW, a bullet optimized for use at .357 Mag. velocities may not perform as expected at .38 Spl. velocities.

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Beware the man with the S&W .357 Mag.
Chances are he knows how to use it.
 
Most 38S/357M revolver loads do use the same bullets, most 9mm/357S do not.

The 9/357S have the same diameter but different ogive shape due to the neck/seating depth on the 357S. The Hornady and Sierra 9mm bullets work fine, the Fed, Rem, Win, Speer 9mm bullets can get you in trouble with setback since they wont contact the whole neck, grab/hold firm enough.

Most 357S bullets are designed to go deep, so the design has to be tweaked to hold down exp so they stay together at the higher speeds.



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There are also differences caused by revolver round vs auto pistol - 38/357 bullets have a crimping groove for the roll crimp used in revolvers vs the 9mm/357sig taper crimp on a smooth sided bullet for the auto pistol.
OAL (Over-All-Length) of the cartridge is also largely determined by the bullet design - how long is the bullet nose above the crimp groove. Some smaller revolvers use a shorter cylinder (think S&W N-frame vs a J-frame), and some auto pistols may not fit long bullet rounds in the magazine.
 
The only exception to this that I can come up is that you wouldn't want to cram a full sized 357 round like a 158 Grain into a 9mm case unless you could sacrafice some of the thrust behind it (due to case size).
 
In the early 70s we had some 9X19 duty rounds that used 158gr at 964fps out of model 39. Rather stout they were but they did expand.

Sam...my favorite 9mm is the 9X32R
 
9mm bullets: .3545 or .355
38spl/357mag:.357
38 S&W:.359 to .361 ( lots of variability)
.357 Sig- I have no idea
crankshaft
paranoia is a great thing to have when they actually are out to get You!
 
Stupid cheapie question. Can a person get away with loading 9mm bullets on a 357/38 round? I know it will affect accuracy but is it safe?
 
They should fire with no safety problems. But, like you said, accuracy would probably be poor, but not atrocious, and velocity may be lower than expected depending on the groove diameter.
 
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by xxero:
38 Spc. and .357 Mag. use bullet diameters from 0.355" to 0.358".
[/quote]

I think you would be hard pressed to find any bullets designed for .357 Mag that are less than .357" in diameter.
 
If you gonner shoot warmish stuff, slug your bbl. There is enough bore diameter variation within guns from the same manufacturing run to make it worth while. Safety and accuracy both affected.

I just miked two batches of Sierra JHC bullets for 38/357, ten from each batch, smallest .3560, largest .3562.

Sam......? What month is it ?

[This message has been edited by C.R.Sam (edited August 18, 2000).]
 
Sam, with all due respect, please check the calibration of your micrometer. I just mic'ed several groups from both Sierra and Speer and all were .3570" +.0001 -.0000. I used a Starrett post micrometer and checked both the zero and against an NBS gauge (.0105).

I did find some JHP's from National Bullet labeled "38 Cal." that are .3560, so my original statement still stands since I didn't include "38", only .357's. But I think the major bullet makers have better QC than NB.

[added]
The boxes for my bullets both said .357. So if yours are labeled something like "for 38/357" without giving the actual size then that would explain it.

BTW, it's October - where ya been lately? Bowling in the Catskills? ;)

[This message has been edited by Mal H (edited August 18, 2000).]
 
Did not Cor-Bon originally load it's 38 Spl with 115 grain 9mm bullets - I disrecall if they had been reswaged or "bumped up" or not.
 
Mal;
Thanx, was overdue for calibration anyway.

First numbers taken with Mitutoyo.

Shop temp 68f so no correction there.

Re-checked the same bullets with Millers Falls and read bout .0001 higher.

Checked em both on 1/2" jo block and they split, Mit under bout half a tenth and the Miller bout half a tenth over.

My little Starrett has ball anvil, checks on the money but iffy on curved surface tho it agrees with the other two.

Don't have a batch code but these came from Sierra later part of 1970.

Sam....didn't used to have to use a loupe.
 
Fud,
One of the target loads for my .357 was a 9mm (355) bullet in a case with 5 g of AA 5#.

That load had virtually no recoil in the .357 and only chronoed at 550 fps. A wimpy load for sure but it did cut holes in the B27 silouette targets we were shooting. As we were shooting for speed, we wanted something with quick recovery time ...and this worked.
 
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