I must concur with Tom. Quite often at LCSCA events we see chamber stamps on guns prior to Marlin-era guns, and the general consensus is that the stamps became common around the time the sub-gauge longer chambers were standardized---mid to late 30's. As far as I know, no one has done a study--either of the Cody or LCSCA (one and the same) records to determine when these stamps were standardized, and Drew's pictures support Tom's statement. Further, I have pictures of a 1914 Eagle-- original-- with the chamber stamp.
