To find the year of proof of your (Post 1975) Browning or Miroku shotgun you’ll need to find the Serial Number. On most over and under shotguns this should be situated under the top lever…

Browning Shotgun Age Look Up Code

and on Semi-Autos somewhere on the receiver...

Browning Shotgun Age Look Up Code Locator

In the Serial number there are two letters together - in the example above this is ZT - this your date code. If you don't have this it is likely that your Gun is an earlier model.

Z 1
Y 2
X 3
W 4
V 5
T 6
R 7
P 8
N 9
M 0
Thus, a gun with PN in the serial number was made in 1989