May 10, 2023
By Stan Trzoniec
There was a time when most of us believed that Smith & Wesson would never bring out a handgun chambered for the .45 ACP. Then, all of a sudden, wham! we were hit with the new Model 645.
This new second-generation of semiautomatics was meant to replace the 4500 series of guns, and it came with major improvements. Constructed entirely of stainless steel with a low-luster, bead-blasted finish, the Model 645 was perfect for the sportsman or for law enforcement duties.
That was back in 1985, and partnered with the Model 745—a single-action version with a carbon blue slide engineered as an IPSC competition gun—they were instant hits, especially after the Sonny Crockett character on Miami Vice used a Model 645 for two seasons.
Still looking for ways to improve the gun, in 1988 the company introduced a third generation of double- action semiautomatics, complete with new serial numbers. The gun shown here is one of those.
The company built the new generation with ergonomics in mind by machining a slimmer grip frame complemented by a new wraparound rubber grip rather than the two-piece one on previous models. Additionally, you could choose between a straight or a curved backstrap.
The trigger guard was extended 0.175 inch forward for more interior room, and the trigger itself was redesigned for a better feel with a “consistent progress on trigger travel” into a comfortable curve instead of a series of peaks and valleys.
The magazines came numbered, and they featured a smoother profile, enhanced styling and combat-style rubber buttpads. They were compatible with second-generation pistols.
The sighting equipment went through a minor redesign. The single dot front sight was a bit sharper in profile, and it was ramped. The rounded-off two-dot rear sight was drift-adjustable, and a Novak low-carry rear sight was an option. There is a slightly raised top rib that runs the length of the slide between the sights, but it is not serrated.
The stainless barrel was the standard five-inch length, with a fixed barrel bushing on the muzzle end for enhanced accuracy and easier field-stripping. The slide release was enlarged, as were the ambidextrous decocking safety levers. Smith & Wesson increased durability with an enhanced firing pin, slide stop and mainspring plungers.
The changes were well received. For instance, Smith & Wesson reported that 47 law enforcement agencies placed orders for the third-generation 645 in 1988.