.38 Super vs. 9mm: Which is Best?

History of the .38 Super Round

This round was introduced in 1929 as an upgraded version of the .38 ACP for the Colt 1911 pistol. The .38 Super launched a 130-grain FMJ bullet at 1,280 feet per second (compared to the .38 ACP’s still fairly hot 1,050 feet per second). From 1929 to 1935, the “Super .38” ruled the roost as the most powerful U.S. handgun cartridge. At the time of the Super’s introduction, only the 7.63 Mauser cartridge churned up more velocity and kinetic energy.

The .38 Super round was initially designed to give law enforcement officers a handgun round capable of better penetration against gangster automobiles and primitive body armor. Had Colt handled things a bit better, this cartridge might be occupying the place in the shooting world that the less powerful 9mm does today.

However, Colt insisted on its .38 Super 1911 headspacing on the cartridge rim rather than the case mouth as it did on the .45 ACP. Without getting technical, rim headspacing produced sub-standard accuracy for the .38 Super compared to the .45 ACP. This prevented it from becoming popular with civilian users. That is until custom barrel makers began making .38 Super barrels that chambered on the case mouth. Today, all makers headspace their .38 Supers on the case mouth, making the round match accurate. But 50 years of building inaccurate .38 Supers had damaged the reputation of the .38 to the point that today only a few manufacturers chamber pistols for it.

Testing the .38 Super and 9mm

In preparing for the testing, I wanted to make sure that I gave the 9mm and .38 Super as much of a head-to-head comparison as I could. Testing included running rounds across the chronograph and shooting 25-pound blocks of moist modeling clay.

The .38 Super Wilson Combat Sentinel has a 3.6-inch barrel. While it would have been ideal to have another Wilson pistol in 9mm with that barrel length, I didn’t have that option. The handgun with the closest barrel length I had on hand was a SCCY 9mm CPX-2 with a 3.1-inch barrel. There would likely be little difference in terms of ballistic performance with only a half-inch variation in length.

Wilson Combat furnished the ammunition for both calibers from its fine line of Custom ammunition. Both the 9mm and .38 Super use a Barnes 115-grain TAC-XP solid copper hollow-point bullet. The .38 Super +P+P and +P+ are designators identifying ammunition as carrying a higher internal pressure than is standard for ammunition of its caliber. load is rated at 1,335 feet per second from a 5-inch barrel, which yields 455 foot-pounds of energy at the muzzle. The 9mm +P load was from the Pinnacle line. Wilson optimized it for top performance in 9mm handguns with 4-inch (or less) barrels. Velocity from a 4-inch barrel was listed as being 1,060 feet per second, which yields 287 foot-pounds of energy at the muzzle.

While the .38 Super is a “niche” cartridge these days, it is still a great performer and does, in fact, outperform the 9mm — all while being just as controllable.

I ran both rounds across the chronograph. One of the most significant things I found with Wilson Combat Custom ammo is its consistency. Both the .38 Super and 9mm loads exhibited little variation in measured velocities. It’s a sign of careful loading and attention to detail one would expect from Wilson. Wilson Combat loads its ammo in-house and doesn’t farm out to unnamed manufacturers, which explains a great deal.

9mm vs. .38 Super: The Data

Velocities for the .38 Super for five shots from the 3.6-inch barrel ran 1,285; 1,287; 1,281; 1,275 and 1,275 feet per second. That’s an average velocity of 1,280 feet per second for an impressive 418 foot-pounds of energy at the muzzle. The 9mm velocities from the 3.1-inch SCCY barrel ran 977, 994, 979, 993 and 1,020 feet per second for an average velocity of 992 feet per second and 251 foot-pounds at the muzzle. It is clear the .38 Super has the ballistic edge in terms of velocity and energy over the 9mm, even when fired from short-barreled handguns. But how would that difference look in equal 25-pound clay blocks?

I fired into both blocks from 20 feet. The .38 Super round penetrated 10 inches into the block and almost exited. The teardrop-shaped cavity it left behind was 5 inches in diameter at the maximum point, proving it to be an effective defensive load.

The 9mm surprised me. I expected a greatly reduced cavity in the clay due to less muzzle velocity. While the size difference was significant, it was not as drastic as expected. The 9mm 115-grain load penetrated the entire length of the block (10.5 inches) and produced a cavity of 4.25 inches at its widest point in the same teardrop shape. While not at the same power level as the .38 Super, the Wilson Combat 115-grain Pinnacle load should also prove to be an effective defensive load.

.38 Super Pros:

• High velocity and energy for superior stopping power
• Balanced recoil for better control
• Effective penetration, making it a reliable self-defense option

.38 Super Cons:

• Niche availability in terms of firearms chambered for .38 Super
• Limited popularity may affect ammunition accessibility

9mm Pros:

• Widely popular, leading to abundant firearm options
• Adequate stopping power with reduced recoil
• Ammunition availability is widespread

9mm Cons:

• Slightly lower stopping power compared to the .38 Super
• Limited penetration in certain scenarios

Choosing the Best Round for Defense

In the showdown of 9mm vs. .38 Super for self-defense, it’s evident that the .38 Super holds the edge in terms of raw power. The key is finding the right balance between stopping power and controllability. If you value a caliber that leans towards superior velocity and energy without compromising control, the .38 Super is a commendable choice.

However, the widespread popularity of the 9mm, coupled with reasonable stopping power and manageable recoil, make it a practical choice for many self-defense enthusiasts. It all boils down to personal preference, firearm availability and your comfort level with the trade-offs between power and control.

Remember, the best self-defense caliber is the one you can handle effectively. Whether you lean toward the timeless reliability of the 9mm or the historical prowess of the .38 Super, make an informed decision based on your needs, preferences and the dynamics of your self-defense scenarios.

Sources

Wilson: WilsonCombat.com