My S&W Model 36-1 Round Butt SN# J6418XX has the Heavy Barrel as illustrated above. Bought new 1/1980 It's a fine shooter & delight to carry in a proper holster. The 3" barrel is carried vertically in most holsters so no impediment to concealment even with the factory "banana targets". It was my go to when I pulled a shift on the dispatch desk.

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NRA LIFE
Reserve Officer 9yrs