The 2nd Issue of the Model 1 looks similar to the 1st Issue, with several notable differences. The side plate on the 2nd Issue is much larger and irregularly shaped. The profile of the frame is flatter (a likely concession for manufacturing efficiency), and the hammer is one piece. Model 1 2nd Issues retain the flared, square cornered shaped grip and the octagonal tip-up style frame, and at first glance the two issues are easy to confuse.
There are several variations of the 2nd Issue guns. Variants between serial numbers 12,000 through to about 20,000 involve the shape of the side plate (“straight” or “round”), the design of the trigger spring (flat spring, V spring or coil spring), and the number of patent dates on the cylinder (two or three). There was also a decrease in the size of the barrel roll stamps at around serial number 95,000. 2nd Issue marked “2D QUAL’TY” are also seen occasionally.
There were approximately 110,000 2nd Issues produced from 1860 through 1868, with serial numbers ranging from approximately 12,000 (following the 1st Issue) through to approximately 120,000.