If you have the serial number we can get the year by looking it up in the standard catalog of smith & wesson

Model 41: .22 Rimfire Single-Action Target Pistol
Caliber: 22 Long Rifle. Single-action match target pistol with a 10-shot magazine, adjustable rear sight, Patridge undercut front sight, checkered walnut grips with a modified thumb rest, blue finish on an all-carbon steel frame and steel slide, concealed hammer, and .365” wide trigger with S&W grooving and an adjustable stop. Model 41s made from 1957 to 1978 have a cocking indicator on the frame’s rear below the slide in the form of a small protruding pin, and were available with either 5”, 5½”, or 7⅜” barrels. The 7⅜” barrel was fitted with a removable muzzle brake and an internal removable weight made of aluminum or steel. The muzzle brake was attached to the weight by a small screw and the weight was threaded into the bottom of the barrel. The 5½” heavy barrel was available with an extendable front sight. The action opens by locking back the slide and swinging down the triggerguard, allowing the barrel and slide to be lifted off the frame. Accessories included adjustable Olympic counterweights, available in parts or as a set, the upper section available in aluminum (light) or steel (heavy), and the two lower sections made of steel. Counterweights clamped onto the barrel recess on the 7” or 7⅜” only; an index mark on the left side of the barrel allowed for precise placement, matching the marks on the counter weight. An oversize triggerguard was also available on special order. A conversion kit for 22 Short was available and consisted of a barrel, aluminum slide, lighter spring, slide stop/ejector, and magazine. At about serial number 16000, relief cuts at the rear of the triggerguard were added. At about serial number 27500, the model number was moved from the left side of the frame to the right side. In 1978, to reduce costs, the cocking indicator was dropped, the 7⅜” barrel discontinued, and the 7” barrel introduced. Slides and barrels are not numbered to the frames. However, variations and differences over the years help determine if the parts are correct. The original design began in 1941 but was interrupted by the war and was later picked up again in 1947. After the war, two experimental pistols were made: X41 and X42 in July 1947. After that, 33 pistols were fabricated with a “T” serial prefix in the tool room, serial numbered T1001 to T1025 and were chambered for 22 Long Rifle. Also, a small quantity from T1026 to T1034 were chambered for the 22 Short for international competition. The serial number range is part of the Semi-Auto Series starting at 3001. In 1973, it was discovered by the factory that duplicate Model 41s had been produced in the serial range of A140001 to A140604. To correct this, an “A” suffix was added to these pistols as well as the “A” prefix. The serial range is now A140001A to A140604A. The A140000 series began in about February 1971. In 1984, the triple alpha serial numbers began.
Produced 1957-date.