Model 10 question ...serial numbers.

[Xfuzz]

Pictured below are 2 model 10's.
Jillions made.
Top 10 is a dash 6 with serial number range C9923xx
book shows 1967-68 mfg.
Bottom 10 is a dash 5 serial 2D207xx book
shows a 1977 mfg.
Why is the dash 6 and earlier produced gun ?

[Hapworth]

With the 10s, the dashes don't necessarily indicate timeline. The -6 denotes (among other mechanical aspects) the heavy barrel; -5 the tapered barrel. They were made concurrently, so you get examples like yours, where a -6 build predates a -5.

[Xfuzz]

Thanks Hap..

[Mark6005]

Xfuzz some things just aren't fair. 2 of those? Some mighty fine revolvers