This table is the same as the previously published one in 2012, but has been refined to be more accurate.įor 405 406 410 411 420 421 425 426 calibers and their sweep versions Movement needs to have these two characteristics:ġ.
The latest refinement includes extending the table This table is for the 405, 420 and 425 basedĬalibers and is a guide for determining the approximate date of Movements in the 405 410 420 & 425 families has been cracked. Gruen Movement Dating using Movement Serial Number
