When you think of revolvers, chances are that you assume they’re chambered for .357 Magnum, .38 Special, .44 Magnum, or some other traditional caliber. After all, we have revolver cartridges and semi-auto cartridges, and never the twain shall meet. Right?
Well, not exactly. Many of you are probably aware that 9mm and .45 ACP revolvers do exist and are becoming more popular, especially the former. So, let’s look briefly at why we have generally had cartridges for revolvers or semi-autos, but rarely both, and how the modern market is changing that situation.
Rimmed and Rimless Cartridges
Traditional revolver and semi-auto cartridges have a couple of basic differences. First, revolver cartridges generally have rimmed cases that hold them in the cylinder properly. They also tend to be longer than semi-auto cartridges. Traditional semi-auto cartridges, like 9mm and .45 ACP, are rimless, making them easier to cycle in a magazine. Magazine dimensions usually limit their length.
Generally speaking, a rimless cartridge designed for a semi-auto pistol will fall deeper into a traditional revolver cylinder’s chamber than it should, making it impossible for the firing pin to strike the primer. That’s even if the chamber was designed for that particular caliber round. Likewise, a revolver round’s rimmed cartridge doesn’t do well in a semi-auto’s box magazine.
Again, we’re speaking in generalities. But necessity and market demand can drive specific changes to traditional practices. The first necessity was a little dustup known as World War I.
The Mother of Invention
The United States entered World War I on April 6, 1917. The nation was woefully unprepared. The rapidly expanding military lacked equipment of all kinds and would fight much of the war with British and French-supplied or repurposed weapons.
Sidearms, like everything else, were in short supply. The M1911 pistol had been in service for several years, but production couldn’t keep up with wartime force expansion. The War Department contracted with Colt and Smith & Wesson to produce .45 ACP-chambered revolvers built on their large frame models to address that shortage. The Colt New Service and the Smith & Wesson Second Model .44 Hand Ejector were the new wheel gun’s base models. Both companies already possessed the necessary tooling, infrastructure, and trained workforce, so the new guns could enter production almost immediately.
The .45 ACP chambering, matching the M1911, was necessary for efficient logistics. Smith & Wesson initially machined shoulders into their chambers to hold the rimless case, but they caused ejection issues. S&W solved the problem by inventing half-moon clips, which both companies adopted. Half and full moon clips are still used very effectively today.
318,432 Model of 1917 Revolvers, chambered in .45 ACP, were made between 1917 and 1919, when the companies discontinued production. Colt or Smith, both models served well, and many were refurbished and retained in US arsenals. Tens of thousands served with military police and even some combat units in World War II. 20,000 were sent to Great Britain in 1940 after the British Army lost all its weapons and equipment at Dunkirk. Military demand died after 1945, but the Model of 1917 proved that rimless semi-auto cartridges could thrive in revolvers.
Modern Demands
Today, 9mm is the world’s most popular handgun cartridge. .45 ACP comes in at number two. That popularity means that every ammo manufacturer makes both cartridges, especially 9mm. The 9mm cartridge’s ubiquity makes it relatively affordable, especially compared to traditional revolver rounds like .357 Magnum. 9mm is less powerful than .357, but it is more effective than .38 Special, which is the other primary defensive revolver cartridge.
Gun companies are responding by introducing ever more revolver choices in 9mm, with some .45 ACP models available too. These guns are purpose-built for our two rimless cartridges. Some require moon clips while others do not.
9mm revolvers may seem weird, but that’s just because they’re largely unfamiliar. .45 ACP seems less strange, but maybe that’s because I’ve always wanted a Model 1917 and so many revolvers are already chambered in some form of .45 caliber cartridge. Weird or not, those chamberings make sense in a market where revolvers seem to be staging a comeback. After all, expensive ammo likely hurts revolver sales. Why not do something about that?
With that in mind, let’s look at a few revolvers chambered for 9mm and .45 ACP. The numbers are few but judging by what we saw and heard at SHOT Show 2025, there are more on the way.
Ruger LCR 9mm
The Ruger LCR is a proven, lightweight pocket revolver available in several calibers, including 9mm. The designers’ shrewd use of polymer and steel make the LCR very light at 17.2 ounces, and the 1.87-inch barrel offers maximum concealment. The LCR wouldn’t be my primary, except in extreme circumstances, but it’s a capable backup. The gun ships with three moon clips.
Ruger SP101 9mm
Like its smaller brother, the Ruger SP101 has several caliber choices beyond 9mm. The gun is sized like a classic snubby, with a 2.25-inch barrel and a five-round capacity. It also ships with three moon clips.
Taurus 905 9mm
The Taurus 905 is interesting as it comes in two distinct configurations: an exposed hammer snubby and a 3-inch-barreled concealed-hammer TALO Edition that draws heavily from the company’s Defender line. Both have a 5-round capacity and ship with Taurus Stellar Clips, though standard moon clips are also compatible.
Charter Arms Pit Bull 9mm, .40 S&W, and .45 ACP
Charter Arms offers the Pit Bull in several barrel lengths: 2.2, 2.3, 2.5, 4.2, and 6 inches. The gun’s dual coil spring extractor assembly allows easy cartridge insertion and retention without moon clips. The Pit Bull is also chambered for three rimless semi-auto cartridges: 9mm, .40 S&W, and .45 ACP. Not every configuration offers all three chamberings.
Ruger Redhawk 5050 .45 ACP/.45 Colt
The Redhawk is Ruger’s well-proven big bore revolver line, and the aptly named Redhawk Model 5050 is unique in that it can fire both .45 ACP and .45 Colt equally well. The six-round capacity offers plenty of firepower (for a revolver), and the heavy, 44-ounce stainless-steel frame means the kick isn’t so bad. This is not a concealed carry gun, but you could do it if you really wanted to. The Redhawk 5050’s availability is always limited, so it’s a little harder to find than the others on this list. The gun ships with three moon clips.
Ruger also offers a Super Redhawk, Super GP100, and GP100 Match Champion in 10mm Auto, with matching moon clips.
A New Trend?
Revolvers seem to be making a comeback. I’ve recently started getting into some wheel guns after years of indifference. I like how they work, their reliability, and how they have some personality about them. It just makes sense that gunmakers would chamber them in the world’s most popular handgun cartridges.
Time will tell whether 9mm and ,45 ACP revolvers catch on. But I think that expanding the cartridge choice is smart. People may start looking at revolvers more seriously if they fit better in established self-defense systems. A common cartridge provides that opportunity.
