Asked in Savage Arms and J. Stevens
What is the age a Stevens-Savage Model 311 double barrel with the number Z 5?
If it is marked with both the Stevens and Savage names and the 311 designation, it was made sometime after 1948. There should be either a letter and number in a circle between the trigger guard and the hinge if made between 1949 and 1968 or a serial number if made after that. The letter codes for 49-68 are A through V, so your Z does not fit in that sequence.