Originally Posted by Engine49guy

Congrats on your K22 OD,
The large R side TM is a dead giveaway as to it being late production as the earliest examples had a small L side TM.

I divide pre war K22's into 4 sub categories:
1) first year production,
SW service stocks, gold bead fs, single rear site screw (no set screw).

2) Change to SS fs insert, SW service stocks, some found with K grip adapters, small L side TM, 2nd rear site set screw.

3) late production OD,
large right side TM, 2nd sight set screw, ( start to see pre war Magna stocks, sometimes the optional taller "Humped back" hammer)

4) K22-40, Magna stocks, new short action, hammer now has a raised visible stop notch, new smooth leaf "Micrometer" rear site unit (post war K-22 sites are grooved).

Nothing is set in stone with SW but this is just how I organize them into sub groups.