The Best Small Revolver: Smith & Wesson's Model 640

According to the author, three words describe Smith & Wesson's Centennial Model 640 .357 Magnum revolver. Plain. Perfect. Beautiful.

June 23, 2025 By Brad Miller PHD

Affiliate Disclosure: This page contains affiliate links. We earn from qualifying purchases.

Some of Smith & Wesson’s most popular revolvers are the small J-Frame guns. They fit the role of personal defender, plinker, and kit gun. They’ve been made in every cartridge from .22 LR to .357 Magnum. In .38 Special and .357 Magnum, they hold just five rounds. These revolvers have three different hammer designs: A traditional exposed hammer for single- and double-action firing; the Bodyguard model has a shrouded hammer, but the hammerspur is accessible, which allows single- and double-action firing; and the Centennial model has an enclosed (internal) hammer that makes it double action only. It is the subject of this report.

The Centennial model was introduced in 1952 chambered in .38 Special on the round-butt steel frame of the Chiefs Special. It had a “lemon squeezer” grip safety on the backstrap. Its name commemorated the company’s 100th anniversary. In 1957 it was renamed the Model 40. The Model 40 was discontinued in 1974 but was reintroduced from 2007 to 2012 as a Classic Series gun. Today, none of the several Centennial version revolvers retains the grip safety.

The popularity of the Centennial design has endured because the enclosed hammer makes the gun snag-free when drawn from a holster, pocket, purse, waistband, or wherever. It also allows the gun to be fired from a pocket or purse because it has no external hammer to snag on obstructions that could disable firing. At present, S&W offers the Centennial design in three different frame materials: aluminum alloy, scandium alloy, and stainless steel. I used the current stainless-steel version (the Model 640) for this article. First made in 1989, the Model 640 was all stainless steel and chambered in .38 Special with a 1.88-inch or 3.0-inch barrel and was rated for +P ammo. The 3.0-inch barrel was dropped in 1993.

The Model 640 was changed to .357 Magnum in 1995 and built on the then-new strengthened magnum J-Frame. It was designated the 640-1 and was the first five-shot .357 Magnum offered on the J-Frame. It featured a 2.12-inch full lug barrel, a smooth trigger, and a pinned black front sight—the configuration it still has today. In 2003 the internal lock was added and designated 640-3. S&W reintroduced the Model 640 in .38 Special in 1997 for the NYPD, and it was tagged the 640-2. The internal lock version of the 640-2 was marked 640-4. Currently, only the 640-1 and 640-3 guns chambered in .357 Magnum are listed on S&W’s website.

Smith & Wesson Model 640-3 — The Plain Jane version (Model 640-3) has the internal lock just above the cylinder release. It allows the gun to be locked to prevent use by unauthorized persons. (Photo provided by author.)

The 2.12-inch full lug barrel on the current 640s allows a longer ejector rod than found on most snubnose revolvers. This pushes the spent cartridges farther out of the chambers. The ejector rod throw length is 0.935 inch, which contrasts to a throw length of just 0.650 inch on a J-Frame Model 642 .38 Special with a 1.88-inch barrel. The Model 640’s ejector throw is nearly as long as those on S&W full-size guns. For example, my Model 686-6 L-Frame six-shot .357 Magnum with a 4.0-inch barrel has an ejector throw length of 0.970 inch.

Current Versions

Sights on the Model 640 — The Model 640 Pro Series (left) has tritium night sights that are dovetailed. The plain and engraved (right) versions have a black, striated ramp front sight and a trench cut rear sight. (Photo provided by author.)

There are currently three iterations of the Model 640: a Plain Jane version (SKU 163690), a Pro Series version (SKU 178044), and a fancified engraved version (SKU 150784). The Plain Jane version is a run-of-the-mill production five-shot wheelgun—no added or special features. The sights are a trench cut rear and a striated black blade front, though the front sight is pinned and can be replaced with something more to your liking, such as fiber optic or tritium. It is the 640-3 version, the only one of the series that has the internal key lock. With its three-finger synthetic grips, it weighs 22.4 ounces.

S&W’s Pro Series 640 features a fluted 2.12-inch barrel and drift-adjustable dovetailed front and rear tritium sights. And the cylinder is cut for moon clips. The frame bears the mark 640-1 because it does not have the internal key lock, so there’s no chance for the lock to be accidentally engaged and disable the gun when you’re in a gunfight. It comes with a synthetic two-finger grip. Like the Plain Jane model, it weighs 22.4 ounces.

Many people consider this version to be the perfect J-Frame gun because it has more visible sights in addition to them being tritium. The company’s website says it has a 10-pound trigger pull. Mine measured 11.25 pounds on a Timney trigger pull gauge. It’s cut for moon clips to be capable for fast, reliable ejection, and reloading. You can carry a moon clip or a speedloader or a speed strip for your reloads, whatever you desire. Moon clips are not required, so you can feed it however you like. It’s a serious gun made for fighting.

Smith & Wesson Model 640 Pro Series — The Pro Series cylinder is cut for moon clips.(Photo provided by author.)

S&W’s fancy engraved 640 is an interesting hybrid of the Plain Jane model and the Pro Series. It has the sights of the Plain Jane gun but lacks the internal key lock, so it has the 640-1 labeled frame. It’s not cut for moon clips. It has a listed weight of 21.8 ounces. The scroll engraving is done by machine with a diamond-tipped tool. The frame, cylinder, and barrel are all engraved, albeit very little of the barrel. It’s not as rich as engraving done by hand by a skilled engraver, but it doesn’t carry the heavy price tag of a hand-engraved gun, either.

It has two-finger bantam wood grips that are engraved. It does make for a pretty gun, worthy of packing to a barbecue. The gun comes in a blue plastic box, but it also comes with a blue felt-lined mahogany wooden presentation case reminiscent of the wood boxes of the old days that were common with premium guns like the Model 29 .44 Magnum.

The price of the engraved gun with the box is pretty reasonable, about $240 more than a Plain Jane, given the engraving work, wood grips, and presentation box. And it’s not so expensive that you would feel guilty about dirtying it up with gunpowder residue from time to time by actually shooting it. I find the lack of the internal lock very appealing and could easily justify using it as a carry gun over the Plain Jane gun with the lock. And don’t we all deserve a little something fancy in our everyday life?

Engraved S&W Model 640 — The engraved gun includes a blue felt-lined mahogany display box. (Photo provided by author.)

Delivers the Goods

As with any snubnose gun, you trade convenience to carry for velocity, but that doesn’t mean these small guns can’t deliver the goods. Being chambered in .357 Magnum, it still has plenty of power for defensive use. As shown in the chart, .357 Magnum 125-grain bullets achieve over 1,200 fps from the 2.12-inch barrel. The Speer 125-grain Gold Dot hollowpoint at 1,265 fps delivers 443 ft-lbs of muzzle energy. And Remington’s heavy 158-grain bullet at 1,120 fps produces 440 ft-lbs of energy. That much force can’t be ignored.

Speeds are also good with .38 Special +P loads. Federal’s 120-grain Punch round was clocked at 906 fps from the short barrel, for 219 ft-lbs of energy. And the speeds with Remington 158-grain lead SWCHP +P and Underwood 158-grain lead SWCHPGC both exceeded 800 fps, which will aid these bullets’ expansion.

I fired the Model 640 Pro from the bench at 10 yards for accuracy. Its sights produce a nice sight picture, but the short sight radius makes getting the precision one would with a longer barrel a challenge. The average five-shot group size with seven different loads was 2.89 inches, which is more than accurate enough for the intended task of defending oneself.

Accuracy data table — (Data provided by author.)

Be warned: Recoil with full-power .357 Magnum ammunition is brutal in these guns, which should come as no surprise given their 22-ounce weights. I’ve found S&W’s three-finger synthetic grip on the Plain Jane that wraps around the back of the frame adequate to cushion the bite of magnums. Hogue and Pachmayr make soft rubber aftermarket grips that will do the same.

S&W’s Centennial Model 640 is a carry gun built to handle the potent .357 Magnum round. It does this well and brings serious power from a snubby to your defense. Buyers can select which features they desire from its three variations. MSRP prices at the time this article was written are $819 for the Plain Jane, $959 for the “perfect” fighting gun, and $1,059 for the engraved beauty. Which one suits you best?