Howdy
Smith and Wesson was the first company to make Top Break revolvers, starting with their large frame 44 caliber American model in 1870. Later, after S&W's patents ran out, other companies got in the game, mostly with small 32 and 38 caliber pocket pistols.
S&W always made the highest quality Top Breaks, but if you want something for shooting modern Smokeless ammunition I am going to recommend you look for an Iver Johnson.
Around 1900 Iver Johnson completely redesigned their line of revolvers with better steels, specifically geared towards Smokeless powder.
This 38 caliber Iver Johnson Safety Hammerless was designed for Smokeless Powder. I paid $100 for it a few years ago, but it would probably cost more today.
There are three ways to tell a Smokeless IJ model from an earlier Black Powder model.
1. The little owl on the grips faces backwards.
2. If you remove the grips, the hammer spring is a coil spring
3. The notches on the cylinder for the bolt have a flat surface on both the leading edge and the trailing edge.
This is an earlier Black Powder era Iver Johnson.
1. Notice the little owl faces forward.
2. If you remove the grips, the hammer spring is a leaf spring.
3. The cylinder notches only have a flat surface for the bolt on one surface, the hand keeps the cylinder from rotating backwards.
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I know several posters will probably mention that modern Smokeless 38 S&W and 32 S&W ammo is loaded light enough for the older guns. Personally, I would never fire any of my old S&W Top Breaks with modern Smokeless ammo, only ammo loaded with Black Powder.
S&W 32 Safety Hammerless
S&W 32 Single Action
S&W 38 Single Action, 2nd Model
S&W 38 Double Action
S&W 38 Safety Hammerless, 3rd Model