[HammerheadSSN663]

The .38 obviously has more powder. So why is the 9mm always considered a superior round to the .38?

I've always wondered and decided to go ahead and ask and take my well deserved abuse.

[Knightrider03m]

I was always told that the .38 was more
:popcorn:

[Guns and more]

I asked that very question after taking my .38 revolver and 9mm pistol to the range. The very wise THR response was this:
1. The .38 is much longer, but not necessarily full of powder.
2. The .38 was designed as a black powder round. Much less "bang" for the buck
3. The 9mm. was designed to use smokeless powder, much more powerful for the smaller amount.

I respected that answer.

[blkbrd666]

I always considered them equivalent.

[WC145]

Different powders, 9mm operates at much higher pressures. More pressure = more velocity = more energy for a given bullet weight.

[oneounceload]

The .38 obviously has more powder

Why do you say that? Because the case is longer? Actually, in many instances, especially when handloading, it has LESS powder.

It was designed for BP....the 9 was not....actually the 9 is more efficient in terms of case capacity versus velocity and power......

[TheVirginian]

It's just an illusion of case size. The pressure is greater in the smaller 9mm case, and the bullet diameter is really the same, so you have very similar results. I'd not favor either round as much as the gun that they fit into.
-Bill

[Hud]

What WC145 said: ".....9mm operates at much higher pressures. More pressure = more velocity = more energy for a given bullet weight. "

SAAMI pressures:

.38 Spec. -------17,000 psi

9mm -----------35,000 psi

Hud

[herohog]

9mm WinMag 9x29 round has the same case length as the .38 and is hotter than 9mm +P+.

The factory load is a 115 grain bullet at around 1500 feet per second. A load of 15.5 grains of #2400 increased the velocity to 1571 feet per second with Sierra 115 grain jacketed hollow cavity projectiles. It will push 147 grain rounds in the 1300's.

Here is a comparison photo I took:

http://herohog.com/images/guns/Compare9mms.jpg

[LightningJoe]

Don't think the .38 Special has more powder, but that's not the issue anyway. Ballistics, you know. 9mm has a bit more oomph in a typical loading. Probably doesn't matter much. They've both been making bad things happen to bad people for a long time.

[Steve C]

So why is the 9mm always considered a superior round to the .38?

For a given bullet weight, the 9mm has higher velocity than a .38 spl. Higher velocity ensures better expansion with hollow point ammo so the 9 is generally a bit more effective. Pistols chambered for the 9mm usually have higher round capacity than the typical .38 spl revolver and are quicker to reload so they have a tactical advantage over the revolver.

Of the 2, the .38 spl is a better target round and will handle heavier bullets due to larger capacity. Revolvers have the advantage in a little better reliability.

[Joshu]

If your going to compare the 9mm and 38 spl, you really need to compare it to +P or +P+ loads. Just about any "Self Defense" Loads are going to be +P. So we have something like...

.38 S&W Special 158 gr (10.2 g) 940 ft/s (290 m/s) 310 ft·lbf (420 J) 17,000 PSI
.38 Special +P 158 gr (10.2 g) 1,000 ft/s (300 m/s) 351 ft·lbf (476 J) 20,000 PSI
.38 Special +P+ 110 gr (7.1 g) 1,100 ft/s (340 m/s) 295 ft·lbf (400 J) >20,000 PSI

vs.

9 mm Parabellum 100 gr (6.5 g) 1,253 ft/s (382 m/s) 349 ft·lbf (473 J) 35,000 PSI
9 mm Parabellum 124 gr (8.0 g) 1,150 ft/s (350 m/s) 364 ft·lbf (494 J) 35,000 PSI


Personaly if I had to pick something in this caliber to carry it would be a .357 stubby. For an auto loader it would a 38 Super.

38 Super

Ballistic performance
Bullet weight/type Velocity Energy
90 gr (5.8 g) JHP 1,557 ft/s (475 m/s) 485 ft·lbf (658 J)
100 gr (6.5 g) FMJ 1,450 ft/s (440 m/s) 467 ft·lbf (633 J)
115 gr (7.5 g) FMJ 1,395 ft/s (425 m/s) 497 ft·lbf (674 J)
130 gr (8.4 g) FMJ 1,305 ft/s (398 m/s) 492 ft·lbf (667 J)
150 gr (9.7 g) FMJ 1,148 ft/s (350 m/s) 439 ft·lbf (595 J)

The SAAMI pressure limit for the .38 Super +P is set at 251.66 MPa (36,500 psi), piezo pressure.

All info copied and pasted shamelessly and lazily from Wikipedia.

[ArmedBear]

So why is the 9mm always considered a superior round to the .38?

Because people don't appreciate the effectiveness of heavier bullets.

To understand why Muzzle Energy is largely hooey, just look at the number above.

Does anyone really think that the same 158 grain bullet going 6% faster is going to be 13% "more powerful"? I'm going to hazard a guess that they'll do about the same thing when they hit the target.

Now look at the 9mm numbers. The 100 grain 9mm bullet is equal to the 158 grain .38+P, just because the smaller bullet is pushed a bit faster? It's not -- not because of the caliber, of course. The .38 wins hands-down IMO in that comparison. I just deliberately chose apples and oranges with the same diameter, to illustrate a point.:)

There are different HP designs, some intended for expansion at lower velocities. It's also not true that the appropriate bullet going 900 fps won't expand. It will expand at 900 if it's designed to.

That said, relying on expansion for defense is problematic in and of itself at any velocity. Expansion assumes that the target fits a certain profile.

Criminal attackers are not made of ballistic gelatin. Maybe if you took a motorcycle-weight leather jacket, a wool shirt and a cotton undershirt, put that in front of the gel, and put some bones in the gel, you'd have something that vaguely resembled a real attacker, outdoors at night. When you consider that, do you still feel good about relying on those expanding bullets to perform like they do in the lab?

And when it comes to Muzzle Energy, consider this. Put a cantaloupe against a wall. Take a length of 3/4" wood dowel and whack the cantaloupe as hard as you can a few times. Then take a few leisurely swings at the cantaloupe with a baseball bat. The energy of the fast whack is probably similar to the energy of the slow swing. Which one will bust open the melon?

A light bullet going faster is not the equivalent of a heavy one going more slowly, even if the energy numbers make it look that way.

Food for thought, that's all.:)

[Joshu]

Another point is, is that these loads are considered safe in all modern chamberings. In other words listed loads at SAAMI pressure limits or below, the cheapest poorly made pistol on the market should be safe to fire them from. This goes double for the 38 Spl. With so many older guns, and cheaper guns on the market in this round, the loads have to be on the milder side. If you were hand loading for a Ruger Blackhawk or a Freedom Arms you could carefully exceed these. Essentialy this is the very reason we have +P loads. +P stands for plus pressure, if your firearm isn't rated for it, you could have a dangerous result. I don't have my reloading manuals here at work for once or I would flip through them.