March 28, 2018
By Joel J Hutchcroft
The S&W Model 66 .357 Magnum K-Frame revolver is now offered with a 2.75-inch barrel. The gun is a stainless-steel, double-action revolver with an adjustable rear sight, synthetic grips, and a six-shot cylinder.
The S&W K-Frame is iconic. The medium-size double-action revolver was first produced in 1896 in .32 S&W Long. Three years later it was chambered for .38 Special. In 1955 a .357 Magnum version was first offered. In 1957 Smith & Wesson gave its handguns a number designation, and the blued-steel medium-frame .357 Magnum model was named the Model 19. The Model 19 was also offered in nickel finish.
In 1970 stainless steel was offered, and in that form it was called the Model 66. Over the years the stainless-steel K-Frame Model 66 has been offered with 2.5-, 3.0-, 4.0-, and 6.0-inch barrels, with weights ranging from 31 to 40 ounces. They were hugely popular with both lawmen and sportsmen.
In 2014 S&W redesigned the Model 66 to incorporate a two-piece barrel setup. Basically, the barrel is composed of an inner liner and an outer shroud. Both parts are steel. This allows S&W to place the barrel shroud over an index tab on the front of the frame and then insert and thread the barrel tube to the frame and to the shroud at the muzzle end, bringing the shroud against the frame as it torques down rather than the traditional threading and crush fitting of the old-style one-piece barrel that requires forcefully tightening to proper index. The two-piece design supports the inner barrel tube at both ends, and according to some experts, it enhances accuracy.
The rear sight is fully adjustable, and it has a plain black blade. The red ramp Baughman-style front sight is pinned into the barrel shroud. The Model 66 uses the K-/L-/N-Frame rounded grip frame that all S&W revolvers currently use.
The stainless-steel cylinder is fluted and holds six rounds of .357 Magnum or .38 Special ammunition. The cylinder measures 1.45 inches in diameter and 1.67 inches in length. The chambers are not counterbored
The Model 66 utilizes Smith & Wesson's keyed locking system. It's an internal lock that is activated via the key slot that is 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 yoke locks to the frame via a spring-loaded ball-detent system, and the solid, full-length, black ejector rod is unsupported. Gone are the old-style cylinder locking lug that was pinned into the barrel lug and the hollow ejector rod. The new system uses a restyled cylinder release latch, which is blackened.
On our sample the single-action trigger pull averaged a consistent 4.0 pounds, 8.0 ounces with my RCBS trigger pull scale. The SA pull was crisp and clean. The double-action pull was 12.0 pounds. By the way, the black trigger is smooth and measures 0.38 inch wide. The hammerspur is checkered, measures 0.38 inch wide, and is blackened.
The Model 66 weighs 33.5 ounces and is 7.8 inches long and 5.5 inches high. Grips are two-piece textured synthetic wraparound, held in place by a single hex-head screw.
The results of my accuracy shooting session with four factory loads- two in .38 Special and two in .357 Magnum- are listed in the accompanying chart. Note that the results are for firing the revolver mounted in a Ransom Rest. Overall average accuracy of the .38 Specials was 2.50 inches, and overall average accuracy of the .357 Magnums was 3.18 inches.
Like I said earlier, the medium-size S&W K-Frame is iconic, and the new 2.75-inch-barreled .357 Magnum Model 66 is perfect for carrying concealed. It's powerful and superbly accurate. It serves admirably as a personal-protection gun and as a trail gun.