I love my stevens 311's. They do kick a bit, mostly from being short stocked like most doubles. I added a pachmyer to mine mostly for length of pull, it really tamed it down, I shoot it all the time for trap and sporting clays. Does it have a letter immediately following the 311 ie. 311A or 311H? I picked up the following somewhere online, sorry the list is out of order, I copied from a table and thats how they ended up.
STEVENS DATE CODE
Double barrel shotguns were date coded between 1949 & 1970. This code can usually be found behind the hinge pin or ahead of the trigger guard on the bottom of the frame and is a small circle with a letter and a number in it.
The letters indicate the year of manufacture starting with "A" in 1949 and ending with "X" in 1970. The letters "O" & "Q" were not used.
Some say this code worked on their single shot shotguns as well, but this is not verified. It appears to have not been used on any other models.
A 1949
I 1957
S 1965
B 1950
J 1958
T 1966
C 1951
K 1959
U 1967
D 1952
L 1960
V 1968
E 1953
M1961
W 1969
F 1954
N 1962
X 1970
G 1955
P 1963
H 1956
R 1964