A.P. Curtis published a two part article in the July 1936 and the March 1938 American Rifleman entitled “Advantages of Short Shotgun Chambers” and stated -
SAAMI, assembled in serious conference on March 26, 1937, passed the following resolution:
“That all guns be marked so that the consumer will be able to tell the chamber length, as for example by marking 2 3/4 inch chamber etc.”
Has anyone seen a 1937-1945 Smith with a standard 2 3/4" chamber that was so marked?