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Smith & Wesson CSX Single-Action-Only 9mm Semiauto Subcompact

The Smith & Wesson CSX old-school single-action-only 9mm semiauto subcompact pistol sports an aluminum grip frame. James Tarr gives us a full review.

Smith & Wesson CSX Single-Action-Only 9mm Semiauto Subcompact

(Yamil Sued photo)

“History never repeats itself, but it does often rhyme.” I was reminded of that wonderful quote from Mark Twain while looking over the new CSX from Smith & Wesson. Since the turn of the century, nearly every new pistol design meant for concealed carry has been a striker-fired model with a polymer frame. It is almost impossible to find a handgun with a new design that has a frame made out of anything other than polymer.

But everything moves in cycles, as they say. Last year, SIG introduced the aluminum AXG grip module for the polymer-framed P320, and I’m not alone in thinking it is somewhere between an improvement and the best iteration of the design. Now we have the brand-new CSX from Smith & Wesson: a subcompact 9mm that is not only old-school single-action only (SAO) but sports an aluminum grip frame.

Compact and subcompact 9mm pistols are the most popular handguns in the modern era, where the vast majority of states allow concealed carry and upwards of 25 have constitutional (permitless) carry. Given that, it’s not surprising that S&W introduced a new subcompact 9mm. It’s the pistol itself that is surprising: a welcome and mostly well-done departure from the norm.

Smith & Wesson CSX Single-Action-Only 9mm Semiauto Subcompact Rear Sight and Beavertail
The sights are steel-bodied and fast to use. A beavertail at the rear of the slide provides a slot for the cocked hammer to rest in, preventing hammer bite. (Yamil Sued photos)

The CSX sports a 3.1-inch barrel, is 6.1 inches long, and 4.6 inches tall with the flush magazine in place. The extended magazine adds less than a quarter of an inch to that. According to my scale, with an empty 10-round magazine inserted, weight is 19.5 ounces. It is basically the same size and weight of the S&W Shield Plus while offering a slightly higher capacity, lower bore, better trigger pull, and what I think are improved ergonomics.

Smith & Wesson refers to this pistol as a “micro-compact,” so this would be a good place for me to point out that there is no technical definition for compact, subcompact, or micro-compact, so S&W can call it whatever they want. However, to my mind, any pistol with “micro” in the definition should fit in a pocket, and the CSX is both too big and heavy for pocket carry. It is eminently concealable, though; it’s just an inch thick everywhere but the thumb safety. It will disappear under any covering garment. I would consider this pistol worthy of the title “subcompact,” and for a subcompact 9mm, it has segment-leading capacity.

Flush magazines hold 10 rounds, and extended magazines hold 12. With the flush magazine in place, most of my pinkie is still on the frame/magazine basepad, but if you’ve got big hands/fingers, you might find your pinkie wrapping around the bottom. The 12-round magazines add so little length (about .22 inch) that I don’t know why you wouldn’t always carry the gun with one of those inserted, buy three more, and let the 10-rounder gather dust in a drawer. With the extended magazine in place, I can easily get my entire hand on the gun. And no, these are not M&P magazines; they’re proprietary to the CSX.

Smith & Wesson CSX Single-Action-Only 9mm Semiauto Subcompact
(Yamil Sued photo)

Both the slide and barrel of the CSX are stainless steel with a black Armornite (nitride) finish. The frame is aluminum with a matte black finish. S&W is saying that the pistol has a reversible magazine release, but that’s not accurate. It has a user-replaceable steel magazine release, and they provide a left-handed magazine release with the pistol.

The CSX sports a bilateral slide release and bilateral thumb safety. In case you’re wondering, while “CSX” doesn’t officially stand for anything, in-house, they were apparently referring to this pistol as the “Chief’s Special X.”

The hammer-fired, single-action-only operating system has allowed the S&W designers to give this pistol a very low bore, and you want that. The lower the bore, the less muzzle rise when you’re shooting; that’s just simple lever and fulcrum physics, and anyone who tells you different is trying to sell you something. There is a nice beavertail at the back of the frame, inside which the hammer nicely nestles when cocked, preventing hammer bite for most everyone.

Unlike with the famous SAO 1911, which has a sliding trigger, the polymer trigger of the CSX pivots at the top. However, it has a nearly flat face (with a safety lever on the front), so it provides a single-action feel. Trigger pull on my sample was a little mushy (when compared to a 1911, which has all steel trigger components) but more than acceptable, with a total pull weight of 6.5 pounds — just under S&W’s spec of 7. I would prefer a lighter trigger, but it was far from a hindrance. The bilateral thumb safety can be engaged whether or not the hammer is cocked.

Smith & Wesson CSX Single-Action-Only 9mm Semiauto Subcompact Front Sight and Trigger
(Yamil Sued photo)

You’ll see Smith & Wesson M&P features and styling cues in the slide of the CSX, with some inspiration from the 1911 as well. There are angled serrations front and back. The very rear of the slide, behind the serrations, is slightly wider to provide a bit more grip. S&W started this with their M&P 380 EZ pistol.

The slide has a flat top, with serrations running down the center. You see this on old-school custom 1911s, and I really like the look of it. Ostensibly, it was done to “cut glare,” but it adds style more than anything. The slide (and the rest of the pistol as well) is very size efficient, much like the 1911. Proportionately, the grip looks a little big for the slide. But trust me, it’s better than the other way around.


Atop the CSX, you’ll see S&W’s standard M&P-style sights. They have steel bodies and white dots and are big enough to use at speed. For a subcompact pistol, they are very nice. Personally, I would prefer a plain black rear sight, but it’s easy to black out those dots with a paint pen.

Immediately upon this pistol’s announcement, there were people on social media bemoaning its lack of a frame rail and a slide that’s not “optics ready.” My response? If you’re trying to attach a red dot and a light to a subcompact pistol, you’re missing the point. I think white lights and red dots on carry guns are a bad fad anyway, but they’re completely out of place on what its manufacturer has labeled a “micro-compact pistol.” This is a pistol built for concealment and personal defense at close range. The lack of a rail and optics mounting on the CSX is a feature, not a bug.

Smith and Wesson CSX Single-Action-Only 9mm Semiauto Subcompact Grip and Magazine
The CSX feeds from 10- or 12-round mags, which is high capacity for a pistol this size. (Yamil Sued photo)

Three things are unusual about this pistol: the aluminum frame, the grip angle, and the single-action-only operating system. Let’s take those in reverse order.

A SAO operating system requires the pistol to have a cocked hammer before pulling the trigger. If the hammer is down, the pistol is just a very expensive paperweight. SAO means the trigger pull is going to be shorter, lighter, crisper, and the same every time, which is why so many people prefer SAO pistols for self-defense.

However, SAO pistols are their own unique animal. There is no completely safe way to lower the hammer on a loaded round with the CSX, and that’s just fine because it’s not something you should do or ever want to do. Single-action pistols should be carried “cocked and locked” (otherwise known as Condition One), but that cocked hammer scares a lot of people, and they end up carrying guns like this with the hammer down. No, don’t do it — ever.

If you’re going to carry a pistol for self-defense, it should be carried in such a manner that you can draw and fire it with one hand, just in case. This means if you’re carrying a CSX, you should be carrying it cocked and locked with the hammer cocked and the thumb safety engaged.

If you don’t feel safe carrying a pistol with a cocked hammer, carry a different gun. Buy an M&P Shield Plus; they are awesome pistols. But there’s no reason not to feel safe with the CSX. That cocked hammer might look scary to the untrained eye, but a CSX in Condition One is no less safe than the average striker-fired gun. It comes equipped with that manual thumb safety and an internal firing pin safety in addition to the safety lever on the trigger.

Smith & Wesson CSX Single-Action-Only 9mm Semiauto Subcompact Barrel
(Yamil Sued photo)

The second surprising thing about this pistol is the grip angle. Seeing as Smith & Wesson is the manufacturer of the highly successful M&P pistol, I was expecting an M&P grip angle (which is very similar to the 1911 grip angle). But no, the CSX sports a more aggressive grip angle much closer to that of the ubiquitous Glock.

Most new pistol introductions have a 1911 grip angle, which is slightly closer to vertical than the Glock — not the CSX. Personally, I love it, but not everyone will. Between the grip angle and the very low bore, I found this pistol pointed very naturally for me.

Now let’s come to the elephant in the room: the aluminum frame. Why would you want an old-fashioned aluminum frame instead of polymer? Aluminum can add recoil-reducing weight … but this pistol is barely heavier than the polymer-framed Shield/Shield Plus. I believe having a frame big enough for your whole hand, as you get with this pistol, is more important for recoil management. Specifically, metal-framed guns just feel different than those with polymer frames. They feel more solid in the hand, and there is a definite difference in recoil impulse. Polymer tends to flex a tiny bit under recoil; aluminum doesn’t. All things being equal, metal-framed guns have a sharper recoil impulse — perhaps a bit harder but over a shorter period of time. Combined with the low bore and single-action trigger, it makes for a very quick-shooting pistol.

The front of the frame sports an aggressively textured inset polymer grip panel. The CSX offers replaceable polymer backstraps with the same aggressive texturing. The smooth areas on the frame concerned me, but between the texturing front and back, the pistol just won’t move in your hand when shooting.

Not that you’re going to be doing speed reloads with a subcompact (that’s the point of the higher capacity, after all), but the beveled magazine well was a nice touch.

Smith & Wesson CSX Single-Action-Only 9mm Semiauto Subcompact James Tarr
(James Tarr photo)

I had a great time at the range. Bore height off the hand is the same or lower than a Glock 9mm, which means low. Recoil is as much straight back as it is muzzle rise. I put several hundred rounds through this pistol, which is built to the same duty-tough standards as S&W’s M&P pistols.

Between the good sights, the relatively crisp trigger, and the ability to comfortably get my whole hand on the pistol with the extended mag in place, I found it shot more like a mid-sized pistol than something that is advertised as a “Micro-9.” I discovered I liked this pistol much more in person than I thought I would after looking at photos. If you find one of these at your local gun store, put it in your hand. Trust me.

I love everything about this pistol, except for one thing: the thumb safety. This pistol should be carried cocked and locked or not at all, and part of the manual of arms of a single-action auto is being able to draw the pistol one-handed and deactivate the thumb safety as part of the draw stroke. Gunsmiths have been enlarging thumb safeties on 1911s for over half a century to make this easier.

The engineers at Smith & Wesson went the opposite route, making this thumb safety diminutive and petite. It is clear that Smith & Wesson’s primary consideration when designing the bilateral steel thumb safety was compactness. It hugs the lines of the slide. However, when it comes to 1911-style thumb safeties, compactness and functionality are usually enemies. S&W proudly advertises that the bilateral levers only add .11 inch to the total width of the gun, which, again, is not what you want for the thumb safety on a SAO pistol. It is not as wide as it should be, in my opinion, to ensure deactivating it under stress. Your experience may differ, but get a gun in your hand and see for yourself.

This is such a wonderful pistol that I am confident either Smith & Wesson or an aftermarket entrepreneur (or both) will soon offer an enlarged, extended thumb safety for the gun. I’m impatient, however, and am already making plans to buy my sample and ship it to a gunsmith and have them weld one up — so that should tell you my true feelings about the CSX. It should be a huge success for Smith & Wesson.

Smith & Wesson CSX Single-Action-Only 9mm Semiauto Subcompact Performance Chart

CSX Specifications

  • Type: Single-action-only semiauto
  • Cartridge: 9mm
  • Capacity: 10+1, 12+1 rds.
  • Barrel: 3.1 In.
  • Overall Length: 6.1 In.
  • Width: 1.12 In.
  • Height: 4.6 In.
  • Weight: 19.5 oz. (with 10-rd. magazine)
  • Finish: Melonite slide
  • Trigger: 7 Lbs. (6.5 lbs. as tested)
  • Sights: 3-Dot, steel
  • Safety: Internal striker/drop, trigger, manual
  • Accessories: 10- and 12-rd. magazines, cable lock
  • MSRP: $609
  • Manufacturer: Smith & Wesson,

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