This is another preview of a coming article. As always, comments welcome!
John
The S&W Model 48 K-22 Masterpiece Magnum Rimfire revolver
(Click for larger view)
This .22 caliber field handgun has been proven effective on small game at ranges up to 100 yards. Its family tree goes back well over 80 years, and although it’s now out of production, good examples can still be found and are eagerly sought after. Here’s how it came about.
In 1939, Smith & Wesson introduced their K-22 Masterpiece, which they believed to be the best of .22 Long Rifle revolvers available at that time. It was developed from the K-22 Target, or as collectors refer to it today, the K-22 First Model, which had been in production since 1931. The K-22 Masterpiece had a new micrometer rear sight, and a shorter action with a very fast lock time (the time from trigger pull to ignition). It was carefully hand-fitted to functional perfection and finished handsomely. Both models were based on what S&W called their K-frame, a medium-sized revolver that was originally purposed for the .38 Special cartridge way back in 1899. Later, in 1957, this newer .22 LR gun became the Model 17 Masterpiece, and it continued to be an outstanding target revolver.
In 1959, Winchester/Olin developed a new and more powerful .22 rimfire cartridge they called the .22 Winchester Magnum Rimfire. Its bullet differed from that of the .22 LR style by using a slightly greater diameter that had no smaller heel. With the .22 LR, just the heel of the bullet is seated in the case, making the case and bullet the same external diameter. This newer bullet was seated into its case the same as centerfire rifle cartridges, with the case being larger in diameter than the bullet. Necessarily, this made the chambers for this new rimfire cartridge larger in diameter as well as having to be longer than those for the .22 LR. The .22 WMR wasn’t intended for target work, but was calculated to be an outstanding rimfire small game cartridge suitable for both rifles and handguns.
Smith & Wesson saw an opportunity, and they seized it. The cylinder for their Model 17 was long enough to accommodate the new magnum rimfire round. It was simple to ream out the cylinders for the longer length and diameter, and broach the barrels for .224” diameter bullets. This was the same dimension used for .22 centerfire cartridges, instead of .222” as used for the .22 LR. These simple steps created a new Masterpiece revolver that was ideal for small game work in the field.
The S&W Model 48 K-22 Masterpiece Magnum Rimfire revolver, chambered in “.22 MRF,” was introduced in May, 1959 with the first serial number being K348746. Its initial catalog listing was in August of that year. “What’s with the ‘MRF’ name?” you may ask. That stands for Magnum Rim Fire, and it’s marked that way on the barrel. My wild guess for the reason is that S&W didn’t want a hint of another firearms manufacturer’s name on their guns! At any rate, the new revolver was offered with three barrel lengths, 4”, 6”, and 8 3/8”. The 4” barrel had a ramped, or Baughman style, front sight. The other two had front sights that were upright, or Patridge style. The 6” barrel was the best seller. The Model 48s were visually almost identical to the .22 LR Model 17s. These were carbon steel guns, and standard-equipped with walnut Magna stocks rather than the larger target style. Almost all were high-polish blued, although a very few were nickel-plated. They had cylinder capacities of six rounds, full-length serrated barrel ribs, fully-adjustable target rear sights and grooved triggers with adjustable trigger stops. The cylinder chambers were recessed to accept the cartridge rims, and the hammer noses were flat, hitting spring-loaded internal firing pins. The earlier guns, prior to 1982, had transversely-pinned barrels to maintain barrel clocking. Barrel pinning was then dropped in the interest of manufacturing economy. The front and back straps of the frames’ grips were also grooved. The right side of each barrel was stamped “22 M.R.F. CTG.” The barrels had a slight straight constrictive taper from frame to muzzle. The serial number is stamped on the bottom of the frame’s grip.
Model 48s went through a series of engineering changes over the years, and these had different “dash numbers” such as “48-2”, “48-3,” etc. These designations were stamped on the frame in the cutout for the yoke on which the cylinder is mounted. Here are the dash numbers, and the changes they specified. 48-1, in 1959, changed the extractor rod thread from right hand to left hand. 48-2, in 1962, eliminated the screw in the trigger guard, and modified the cylinder stop. 48-3, in 1967, relocated the rear sight leaf screw, and in 1968, the “diamond” pattern in the stocks’ checkering was eliminated. 48-4, in 1977, moved the gas ring from the yoke to cylinder, and in 1982, barrels were no longer pinned. A 48-3 model equipped with a 6” barrel and shipped in October, 1975, is illustrated here.
It’s worth noting that S&W initially offered auxiliary cylinders chambered for .22 LR as an option, but this practice was soon dropped. As you may know, firing .22 short, long or LR cartridges in .22 magnum chambers is dangerous, and definitely not recommended.
Winchester’s initial specs for the .22 WMR, fired from a 6.5” test barrel, had a 40-grain bullet moving at a muzzle velocity of 1550 feet per second, with a concurrent muzzle energy of 213 foot-pounds. And a word of warning to first-time users: this is NOT your grandfather’s .22 revolver. This baby is LOUD when it’s fired. Ear protection is highly recommended. This is not a target gun; it’s a rootin’ tootin’ field gun ready to do damage at extended distances. Recoil, on the other hand, is not bad, with the 6-inch version weighing in at about 2 ½ kick-absorbing pounds.
The original Model 48 was manufactured until 1986. In 1989, a stainless steel version of it was designated as the Model 648. It had a 6” full under-lug barrel. Manufacture of this item ceased in 1994. The year 2003 saw the introduction of the Model 648-2, which was equipped with an internal safety lock, displaying an “ugly keyhole” just above the cylinder release. This politically-inspired item is disdained by many shooters, including myself, as unnecessary, potentially unreliable, and unsightly. This one didn’t last long, and production was terminated in 2005. S&W, in recent years, has introduced “Classic” re-issues of certain revolvers from the past. A Model 48 Classic came on the market in 2010. It has been available with 4” or 6” barrels, and as with the original Model 48s, it has no under-lug. As of this writing, the 4” variation is still available. These are blued and equipped with target-style stocks. The hammer area of the frame has a different slope as a nod to the internal firing pin and lock mechanism used on most of S&W’s modern revolvers. The Model 648 has also been re-introduced with a 6” barrel and an 8-round cylinder in 2019. These guns regrettably continue to have that controversial internal lock.
The .22 magnum rimfire cartridge has had a resurgence of interest in the last several years, as ammo has become more available and a number of new firearms have been chambered for it. It’s admittedly more expensive than .22 long rifle rounds, but many, including myself, love it for the increased power and reach it provides. In a handgun, you could never ask for better than the old Model 48 revolvers, introduced more than 60 years ago. They are very desirable classics if you have a yearning for a .22 magnum-chambered revolver.
(c) 2019 JLM
John
The S&W Model 48 K-22 Masterpiece Magnum Rimfire revolver
(Click for larger view)
This .22 caliber field handgun has been proven effective on small game at ranges up to 100 yards. Its family tree goes back well over 80 years, and although it’s now out of production, good examples can still be found and are eagerly sought after. Here’s how it came about.
In 1939, Smith & Wesson introduced their K-22 Masterpiece, which they believed to be the best of .22 Long Rifle revolvers available at that time. It was developed from the K-22 Target, or as collectors refer to it today, the K-22 First Model, which had been in production since 1931. The K-22 Masterpiece had a new micrometer rear sight, and a shorter action with a very fast lock time (the time from trigger pull to ignition). It was carefully hand-fitted to functional perfection and finished handsomely. Both models were based on what S&W called their K-frame, a medium-sized revolver that was originally purposed for the .38 Special cartridge way back in 1899. Later, in 1957, this newer .22 LR gun became the Model 17 Masterpiece, and it continued to be an outstanding target revolver.
In 1959, Winchester/Olin developed a new and more powerful .22 rimfire cartridge they called the .22 Winchester Magnum Rimfire. Its bullet differed from that of the .22 LR style by using a slightly greater diameter that had no smaller heel. With the .22 LR, just the heel of the bullet is seated in the case, making the case and bullet the same external diameter. This newer bullet was seated into its case the same as centerfire rifle cartridges, with the case being larger in diameter than the bullet. Necessarily, this made the chambers for this new rimfire cartridge larger in diameter as well as having to be longer than those for the .22 LR. The .22 WMR wasn’t intended for target work, but was calculated to be an outstanding rimfire small game cartridge suitable for both rifles and handguns.
Smith & Wesson saw an opportunity, and they seized it. The cylinder for their Model 17 was long enough to accommodate the new magnum rimfire round. It was simple to ream out the cylinders for the longer length and diameter, and broach the barrels for .224” diameter bullets. This was the same dimension used for .22 centerfire cartridges, instead of .222” as used for the .22 LR. These simple steps created a new Masterpiece revolver that was ideal for small game work in the field.
The S&W Model 48 K-22 Masterpiece Magnum Rimfire revolver, chambered in “.22 MRF,” was introduced in May, 1959 with the first serial number being K348746. Its initial catalog listing was in August of that year. “What’s with the ‘MRF’ name?” you may ask. That stands for Magnum Rim Fire, and it’s marked that way on the barrel. My wild guess for the reason is that S&W didn’t want a hint of another firearms manufacturer’s name on their guns! At any rate, the new revolver was offered with three barrel lengths, 4”, 6”, and 8 3/8”. The 4” barrel had a ramped, or Baughman style, front sight. The other two had front sights that were upright, or Patridge style. The 6” barrel was the best seller. The Model 48s were visually almost identical to the .22 LR Model 17s. These were carbon steel guns, and standard-equipped with walnut Magna stocks rather than the larger target style. Almost all were high-polish blued, although a very few were nickel-plated. They had cylinder capacities of six rounds, full-length serrated barrel ribs, fully-adjustable target rear sights and grooved triggers with adjustable trigger stops. The cylinder chambers were recessed to accept the cartridge rims, and the hammer noses were flat, hitting spring-loaded internal firing pins. The earlier guns, prior to 1982, had transversely-pinned barrels to maintain barrel clocking. Barrel pinning was then dropped in the interest of manufacturing economy. The front and back straps of the frames’ grips were also grooved. The right side of each barrel was stamped “22 M.R.F. CTG.” The barrels had a slight straight constrictive taper from frame to muzzle. The serial number is stamped on the bottom of the frame’s grip.
Model 48s went through a series of engineering changes over the years, and these had different “dash numbers” such as “48-2”, “48-3,” etc. These designations were stamped on the frame in the cutout for the yoke on which the cylinder is mounted. Here are the dash numbers, and the changes they specified. 48-1, in 1959, changed the extractor rod thread from right hand to left hand. 48-2, in 1962, eliminated the screw in the trigger guard, and modified the cylinder stop. 48-3, in 1967, relocated the rear sight leaf screw, and in 1968, the “diamond” pattern in the stocks’ checkering was eliminated. 48-4, in 1977, moved the gas ring from the yoke to cylinder, and in 1982, barrels were no longer pinned. A 48-3 model equipped with a 6” barrel and shipped in October, 1975, is illustrated here.
It’s worth noting that S&W initially offered auxiliary cylinders chambered for .22 LR as an option, but this practice was soon dropped. As you may know, firing .22 short, long or LR cartridges in .22 magnum chambers is dangerous, and definitely not recommended.
Winchester’s initial specs for the .22 WMR, fired from a 6.5” test barrel, had a 40-grain bullet moving at a muzzle velocity of 1550 feet per second, with a concurrent muzzle energy of 213 foot-pounds. And a word of warning to first-time users: this is NOT your grandfather’s .22 revolver. This baby is LOUD when it’s fired. Ear protection is highly recommended. This is not a target gun; it’s a rootin’ tootin’ field gun ready to do damage at extended distances. Recoil, on the other hand, is not bad, with the 6-inch version weighing in at about 2 ½ kick-absorbing pounds.
The original Model 48 was manufactured until 1986. In 1989, a stainless steel version of it was designated as the Model 648. It had a 6” full under-lug barrel. Manufacture of this item ceased in 1994. The year 2003 saw the introduction of the Model 648-2, which was equipped with an internal safety lock, displaying an “ugly keyhole” just above the cylinder release. This politically-inspired item is disdained by many shooters, including myself, as unnecessary, potentially unreliable, and unsightly. This one didn’t last long, and production was terminated in 2005. S&W, in recent years, has introduced “Classic” re-issues of certain revolvers from the past. A Model 48 Classic came on the market in 2010. It has been available with 4” or 6” barrels, and as with the original Model 48s, it has no under-lug. As of this writing, the 4” variation is still available. These are blued and equipped with target-style stocks. The hammer area of the frame has a different slope as a nod to the internal firing pin and lock mechanism used on most of S&W’s modern revolvers. The Model 648 has also been re-introduced with a 6” barrel and an 8-round cylinder in 2019. These guns regrettably continue to have that controversial internal lock.
The .22 magnum rimfire cartridge has had a resurgence of interest in the last several years, as ammo has become more available and a number of new firearms have been chambered for it. It’s admittedly more expensive than .22 long rifle rounds, but many, including myself, love it for the increased power and reach it provides. In a handgun, you could never ask for better than the old Model 48 revolvers, introduced more than 60 years ago. They are very desirable classics if you have a yearning for a .22 magnum-chambered revolver.
(c) 2019 JLM
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