Here is from Gun Digest Gun Values:
Model 1877 was Colt's first attempt at manufacturing a double-action revolver. Shows a striking resemblance to Single Action Army. Sales on this model were brisk, with over 166,000 produced between 1877 and 1909. Chambered for two different cartridges; .38 Colt known as Lightning" and .41 Colt as "Thunderer". (Also about 300 to 350 made in .32 caliber as the "Rainmaker".) Standard finishes are blued, with case colored frame and nickel plate. Bird's-head grips are of checkered rosewood on early guns and hard rubber on majority of the production run. Barrel lengths most often encountered are 2.5" and 3.5" without an ejector rod and 4.5" and 6" with rod. Other barrel lengths from 1.5" through 10" were offered. Model 1877 holds 6-shots in either caliber. There were quite a few different variations found within this model designation. Values furnished are for standard variations. Antiques made before 1898 would be more desirable from an investment standpoint. These revolvers have a reputation as "watchmaker's nightmares" and non-functioning examples command substantially reduced prices. NOTE: Add 25 percent premium for blued guns; 50 percent premium for shorter than 2.5"; 10 percent for .41-caliber "Thunderer"; 50 percent for over 6" barrel; 20 percent for London barrel address; 50 percent for .32-caliber; 10 percent for rosewood grips.
Model 1877 was Colt's first attempt at manufacturing a double-action revolver. Shows a striking resemblance to Single Action Army. Sales on this model were brisk, with over 166,000 produced between 1877 and 1909. Chambered for two different cartridges; .38 Colt known as Lightning" and .41 Colt as "Thunderer". (Also about 300 to 350 made in .32 caliber as the "Rainmaker".) Standard finishes are blued, with case colored frame and nickel plate. Bird's-head grips are of checkered rosewood on early guns and hard rubber on majority of the production run. Barrel lengths most often encountered are 2.5" and 3.5" without an ejector rod and 4.5" and 6" with rod. Other barrel lengths from 1.5" through 10" were offered. Model 1877 holds 6-shots in either caliber. There were quite a few different variations found within this model designation. Values furnished are for standard variations. Antiques made before 1898 would be more desirable from an investment standpoint. These revolvers have a reputation as "watchmaker's nightmares" and non-functioning examples command substantially reduced prices. NOTE: Add 25 percent premium for blued guns; 50 percent premium for shorter than 2.5"; 10 percent for .41-caliber "Thunderer"; 50 percent for over 6" barrel; 20 percent for London barrel address; 50 percent for .32-caliber; 10 percent for rosewood grips.
