UPDATE: Pages 244 and 511, SCSW 4th ed.

1996 - August, Model 36-9 JM (J Magnum) frame replaced ALL J frames whether or not chambered for the .357 Mag, 1.6” longer cyl and 1.73” frame window, as well as MIM hammer and trigger.

This includes the 642-1 which is the reintroduction of the 642 on the J magnum frame.

The dead giveaway to the JM frame is the elimination/change of the separate cyl stop lug piece in the lower right corner of the cyl window to the cyl stop integral with the frame.

__________________
Jim
S&WCA #819