April 01, 2020
By Joel J. Hutchcroft
The .22 Winchester Magnum Rimfire (WMR), a.k.a. .22 Magnum, is one of my favorite cartridges. Growing up and living my whole life in Illinois, where I have been limited to hunting with rimfires, shotguns, and muzzleloaders (except for coyotes that can be hunted with centerfire rifles), I’ve hunted a lot of small game and varmints with the .22 Magnum. It’s an accurate cartridge, and as more than one old-timer has stated, its ballistics out of a 6.0-inch-barreled handgun are equal to or better than .22 LR ballistics out of a 24-inch-barreled rifle. I’ve lost track of the number of .22 Magnum guns I’ve owned and tested over the years, but two of my favorites were a vintage S&W Model 48 double-action revolver and a Winchester Model 9422 XTR lever-action rifle. However, I think the brand-new S&W Model 648 may have taken over the top slot on my favorites list. I’ll get to why, but first, let’s take a look at the cartridge.
The .22 WMR
Although the .22 Magnum once was our smallest magnum cartridge, that’s not the case today. Introduced in 1959 by Winchester, the .22 WMR can propel a 40-grain bullet at a velocity of nearly 2,000 fps out of a rifle. Modern loadings with lighter-weight, polymer-tipped bullets boast velocities of 2,200 fps. It is an incredibly potent small-game round.
In 6.0-inch-barreled handguns, the .22 WMR churns up velocities running from 1,000 to 1,500 fps depending on the loading. Compared to .22 LR velocities from rifles with barrel lengths running from 18 to 24 inches obtained by shooting subsonic, match, and hunting ammo and chronographing them 12 feet from the guns’ muzzles (actual velocities ranged from 980 fps to 1,340 fps depending on the loading), the .22 WMR is anywhere from 20 fps on the low end to 160 fps on the high end faster. That’s out of a 6.0-inch-barreled handgun. Depending on the specific data, the .22 WMR out of a 6.0-inch handgun barrel produces from 110 ft-lbs to 170 ft-lbs of muzzle energy. That’s definitely enough for shooting small game at typical handgun-hunting distances.
The New Model 648
The original S&W Model 648 revolver was produced from 1989 until 1996 and again from 2003 until 2005, but before it, S&W produced the Model 48 from 1959 until 1986 (it was reintroduced in S&W’s Classics line in 2010). Both the Model 48 and Model 648 were K-Frames, and both originally featured six-shot cylinders. As I stated previously, both were chambered for the .22 Magnum, but an optional .22 LR cylinder was available for the Model 48. The Model 48 was a blued chrome-moly steel revolver (a very few nickel-plated Model 48s were produced, and they command a premium among collectors), and the Model 648 was a stainless-steel revolver. Both models come with fully adjustable rear sights.
Originally, the Model 48 was offered with 4.0-, 6.0-, and 8.38-inch barrels, while the Model 648 came with only a 6.0-inch, full-lug barrel. The Model 48 had checkered walnut grips, and the Model 648 had smooth Goncalo Alves combat-style grips with finger grooves. (Goncalo Alves is a type of nicely figured wood.) In 1994 S&W changed the Model 648 to black Hogue rubber grips with finger grooves. I owned a vintage 6.0-inch-barreled Model 48 in the late 1980s, and twice I have owned original Model 648s. All were excellent guns, but I have to admit, when I heard that S&W was going to reintroduce the Model 648 with an eight-shot cylinder, I knew I had to have one.
Like the original, the new eight-shot Model 648 revolver is offered with a 6.0-inch full-lug barrel, an adjustable rear sight, and a black Patridge front sight. The Patridge sight is a relatively thick, rectangular, flat-topped post named for its inventor, E.E. Patridge, an American champion revolver shooter during the late19th century. Paired with the square-notch rear sight, the Patridge sight is preferred for target shooting because the vertical alignment is very precise. The Model 648’s front sight is pinned into the barrel. The grips are textured black synthetic with finger grooves and the S&W logo molded into both sides. The grip screw has a Torx head.
The full-lug barrel gives the revolver a substantial heft. It weighs 46.2 ounces. That probably seems heavy to a lot of readers in this day and age of lightweight carry guns. But I don’t mind the weight. Serious shooters know that if you can handle the weight, a heavier handgun is easier to hold steady. Also, the 6.0-inch barrel gives the Model 648 a sight radius of 7.25 inches. Generally, the longer the sight radius, the less effect any slight sight-alignment error will have on a target downrange.
The Model 648 uses the K/L/N-Frame rounded grip frame that all S&W revolvers currently use. And the synthetic grips are slim and textured. They wrap around the entire grip frame, and the grip circumference is 5.0 inches directly across from the trigger guard.
The revolver’s cylinder is fluted, and the chambers are countersunk. The cylinder measures 1.45 inches in diameter and 1.62 inches in length, and it rotates counterclockwise.
The revolver utilizes Smith & Wesson’s keyed locking system, which is an internal lock that’s activated by the key slot located just above the cylinder release latch on the left side of the revolver. When engaged, it prevents the hammer from being cocked and the trigger from being squeezed. The cylinder release is the newer style.
The gun I fired for this report had a crisp, clean trigger pull. The single-action trigger pull averaged 4.0 pounds, according to my RCBS trigger-pull scale, and the double-action pull averaged 13.5 pounds. Those figures are based on measuring the double-action pull weight eight times and the single-action pull weight eight times and then averaging the respective results. The trigger’s fingerpiece is smooth, and it measures 0.38 inch wide. The hammerspur is 0.51 inch wide, and it’s checkered.
Eight Is Enough
For my shooting tests of the new eight-shot Model 648, I fired eight loads, and I installed a Wiegand scope mount, which I purchased from Brownells. For the accuracy evaluation, I used my favorite handgun scope. The scope is an old, special-edition Burris 1X with very fine crosshairs and a 7.75-minute black dot reticle proportioned to cover slightly more than the X-ring at 25 yards and the 10-ring at 50 yards of a Bullseye target. That scope was designed by my old boss, Gil Hebard, and produced under a special agreement. Gil was a champion Bullseye competition shooter, and he designed the scope for target shooting. We sold a lot of them back when Bullseye competition was at its height in popularity. I never competed in Bullseye matches, but I’ve done plenty of informal target shooting with this scope.
During my second session with the new Model 648 (a morning of squirrel hunting on my rural property), I used a Weaver 2X handgun scope with a plex reticle. I prefer this type of reticle for small-game hunting because the black dot and fine crosshairs of the Burris Bullseye scope sometimes can be difficult to see against the head and body of a dark-colored “tree-top whitetail” (a.k.a. fox squirrel) if the lighting conditions in the timber are less than ideal. Of course, any number of red-dot optics work great for small-game hunting, too, but in my opinion, the full-lugged, 6.0-inch-barreled Model 648 screams for a full-size handgun scope.
The Wiegand scope mount is easy to install by virtue of the drilled-and-tapped topstrap of the Model 648. The revolver’s factory rear sight has to be removed, but that’s an easy task, and the scope mount installs in just minutes. Three screws hold it securely to the gun’s frame.
I also used an old set of Herrett custom-made wood grips that fit my hand perfectly. Again, these grips were originally designed for target shooting, but I like them so much, I almost always use them on my favorite S&W K-Frame revolvers. They have a palmswell, a palmrest, and a thumbrest that conform to the shape and size of my right hand. I was smart enough to buy two sets back when I worked for Gil, but I probably should have purchased even more. As they say, hindsight is 20/20.
As for the accuracy and velocity results of shooting the eight loads in the eight-shot Model 648, I was pleased that the gun’s overall average accuracy at 25 yards was 1.89 inches. The most accurate load was the Winchester 40-grain JHP ammo, and its five, five-shot groups averaged 0.75 inch. The second most accurate loading was the CCI Maxi Mag +V 30-grain TNT ammo, and its five, five-shot groups averaged 1.50 inches.
One of my favorite .22 Magnum loadings has always been Federal’s 50-grain JHP. Its SKU is 757. A few decades ago Federal called it Classic, and today it is part of the company’s Game-Shok line. Unfortunately, it didn’t shoot as well in the new Model 648 as I had expected. It was in the middle of the pack in terms of accuracy, averaging 2.33 inches at 25 yards. I don’t consider that to be quite accurate enough for head shots on squirrels. Granted, I only fired five, five-shot groups with it, so I plan on doing some more practice with it in hopes that the average will improve. It may have some potential because its single best five-shot group measured 1.12 inches, and afterall, it usually doesn’t take five shots to drop a squirrel. But the Winchester ammo also had higher energy, so I’ll likely keep hunting with it.
Lately, it seems like revolvers of all makes have been surging in popularity. I’m pleased to see that because I’ve always loved revolvers, both double action and single action. The eight-shot .22 Magnum Model 648 is sort of a specialized revolver and may not be for everyone. I see it primarily as a small-game-hunting tool and camp/trail gun, but it’s also great for casual target shooting and plinking. I’m thinking of it as a .22 Magnum masterpiece.
Smith & Wesson Model 648 .22 WMR Revolver SpecsManufacturer:
Smith & Wesson; smith-wesson.comType:
.22 Winchester Magnum RimfireCylinder Capacity:
6.0 in.Overall Length:
5.5 in.Weight, Empty:
Polished stainless steelSights:
Fully adjustable rear, Patridge frontTrigger:
13.5-lb. DA pull, 4.0-lb. SA pull (as tested)Safety:
Key-activated internal locking systemMSRP: