On Smith and Wesson nomenclature. What does the number 2 represent in Model 15-2? I see the model number but have no clue as to what the other number is. I do know it is not barrel length.

Probably 2nd generation.. Like you have the SBE II, Abolt II, ultra carry II, etc.

It denotes small changes in the design and features, such as a pinned barrel, recessed chambers,that sort of thing. There is a table describing all this in my old Gun Parts Corp. Catalog. I have not searched the Numrich/Gun Parts site for the info, but it may be there somewhere.

From Wikipedia:

As the K-38 Combat Masterpiece Revolver Model 15 evolved the following Engineering and Production Changes were made[6]:

1949: K-38 Combat Masterpiece Introduced

1955: Delete upper sideplate screw.

15 (1957): K-38 Combat Masterpiece continued as the Model 15. Stamping of model number

15-1 (1959): Change extractor rod, right hand to left hand thread.

15-2 (1961): Delete trigger guard screw, change cylinder stop.

1964: Introduce 2” heavy barrel.

15-3 (1967): Relocation of rear sight leaf screw.

1968: Delete diamond grips.

15-4 (1977): Change to put gas ring from yoke to cylinder.

15-5 (1982) Pinned barrel eliminated

1986: Introduction of 6” and 8-3/8” barrel.

15-6 (1988): new yoke retention system/ radius stud package/hammer nose bushing.

1988: Discontinue 8-3/8” and 2” barrel.

1992: Discontinue 6” barrel, blue finish only.

15-7 (1994): Synthetic grips introduced, drill and tap frame, change rear seat leaf, change extractor.

1995-96: Delete square butt.

1996: Begin shipments in blue plastic case.

1997: 4” barrel only / Change to MIM thumbpiece / Shipped with master trigger locks / change to MIM trigger.

15-8 (1997): Changes in frame design: cylinder stop stud eliminated / Eliminate serrated tangs / Change to MIM hammer with floating firing pin and change internal lockworks.

1999: Model 15 discontinued Nov. 1999.

2001: Limited run Lew Horton Heritage Series from the S&W Performance Center.

15-9 (2002): Limited run Lew Horton Heritage Series McGivern Models from the S&W Performance Center. 3 Models commemorating Ed McGivern’s world speed records in 1934 with a revolver. All models have a Partridge front sight with Gold Bead, round butt frame with Altamount Fancy checkered service grips of that era, 6” barrel, Ed McGivern commemorative plate mounted on right side of frame, Heritage Series box.

15-10 (2011)[7]: Production re-commenced under Classics Revolvers line, re-tooled, shrouded redesigned barrel, internal trigger lock.

Thanks BA223 this is exactly what I was wanting to learn.