You, as a shooter, get to enjoy an embarrassment of riches when it comes to the variety of calibers you get to enjoy. Whenever you grow weary of the 22 LR/9mm/223 Rem trinity, you can explore rarer cartridges like the 30 Thompson Center, the 17 Ackley Bee, and the 8x50mmR Mannlicher. If this hobby ever bores you, then buddy, that’s your own dang fault. We’ve got important things to think about, like what separates the 45 ACP vs. the 38 Super?

The real issue when looking at these calibers is deciding when you should favor a less common cartridge for the most important application of self-defense? That dilemma is best demonstrated by comparing the extremely popular 45 ACP vs. the relatively obscure 38 Super. They’re both viable cartridges for personal protection, but that one has so thoroughly beaten out the other must mean something.

The 45 ACP

A 45 acp pistol and ammunition on a table

The 45 ACP was designed in 1904 by the great John Moses Browning and went into production the following year. The need for a more powerful pistol cartridge capable of dealing with tenacious threats spurred its development. The Moro Rebellion (1899-1913) that pitted American troops against powerful, determined, and rather drugged up tribal warriors armed with thick wooden shields was a large driving force behind that perceived need.

The 45 ACP owes much of its great popularity to the M1911 pistol. Manufacturers churned out several million of the handguns during the world wars, and accordingly millions of men became intimate with the 45 ACP’s performance. People like what they know and tend to stick to it: Of the five most popular handgun cartridges, only the 40 S&W was introduced in the past 100 years.

The 45 ACP offers several performance benefits. Its muzzle blast, muzzle flash, and 830 fps muzzle velocity are all relatively low, so its recoil is manageable (if not a little less so out of a compact weapon). The standard 230 grain .451” diameter bullet is wide enough to create a devastating wound channel even without expanding. That a 45 ACP’s jacketed hollow point can consistently expand to .75” in ballistic gel, however, makes it nothing to chuckle about when you’re hit by one.

Compared to the now more prevalent 9mm, the 45 ACP’s heavier bullet is less capable of penetrating armor. The larger cartridge is furthermore less convenient for transport, and transporting ammunition is something the U.S. Armed Forces does quite often. Recent technological innovations have made the smaller 9mm’s performance comparable to that of the 45 ACP ammunition, in fact, although we don’t see the classic caliber leaving the self-defense scene any time soon.

The 38 Super

38 Super pistol and ammo on a table

The 38 Super entered production nearly 15 years after the 45 ACP. The cartridge has actually got nothing to do with the 38 Special. Rather, it is a higher pressure loading of Browning’s 38 ACP. The original 38 ACP fires its 130 grain bullet at 1,050 fps; The new and improved 38 Super’s modern propellant charge accomplishes the same but at 1,280 fps.

A 38 ACP and a 38 Super cartridge share identical dimensions. For this reason manufacturers often include a “+P” on the 38 Super’s headstamp. It’s not an overpressure round per se because it’s producing exactly as much pressure as its specs call for. The +P serves as a visual reminder that the 38 Super could very well destroy a 38 ACP pistol that isn’t rated to manage its greater pressure.

The 38 Super was designed specifically for the M1911 pistol. Its high muzzle velocity, flat trajectory, and excellent accuracy quickly earned it a following among law enforcement professionals. They needed ammo capable of penetrating car doors and light armor.

The more powerful 357 Magnum arrived to supersede the 38 Super in 1934, however, and today the 9mm +P has more or less obsoleted the cartridge.

45 ACP vs. 38 Super

45 acp ammo vs 38 super ammo

In the 1980s the 38 Super started becoming increasingly popular among competitive shooters. This was due to its somewhat better accuracy than that of the 45 ACP. The 38 Super’s significantly lighter bullet produces more manageable recoil as well. That is a major factor to consider — if you are concerned about recoil impacting your ability to accurately direct rapid fire, then that alone may make the 38 Super a better choice for you than the 45 ACP.

A Legal Alternative to 45 ACP

The 38 Super is an especially popular self-defense load in Italy and several South American countries. This is the product of legislation rather than objective reasoning, however. Such countries’ governments have banned their citizens from using the same ammunition as military and law enforcement for self-defense. So, the 38 Super is the next best thing they’ve got.

That some consider the 38 Super “next best thing” to the 45 ACP in these places is telling. Certainly, the 38 Super is better at penetrating a barrier like car door thanks to its superior muzzle velocity. However, car doors enter into very few civilian self-defense situations. The general consensus is that the 45 ACP’s bigger, meatier bullet is inherently able to inflict greater damage to a fleshy target. The 45 ACP compensates for its lesser muzzle velocity with a heavier bullet.

There’s the rub. The 45 ACP boasts about the same stopping power, but with faster velocity, the 38 Super wins in terms of accuracy. Self-defense situations nearly only occur when an attacker is very close to their intended victim, though. It is unlikely you will ever need to dispatch of a mugger several dozen yards away. For that reason alone, we would endorse the 45 ACP over the 38 Super for self-defense.

But exceptions are the spice of life. If you are a competitive shooter who puts in countless training hours with the 38 Super, your familiarity with the caliber will serve you well during a violent altercation.

So, What Should You Shoot?

The unsatisfying conclusion to the 45 ACP vs. 38 Super dilemma is that you should try out both calibers and carry the one which you prefer. Maybe you will like neither and gravitate toward the 9mm. Maybe you will renounce firearms completely and decide to master Wing Chun kung fu instead. In that case you had better hope the bad guys in your area are all Bruce Lee fans. You know, because they will honor your self-defense style.