Would like year of production of my savage 300 mod 99 serial352660

You did not supply all needed information so I am just guessing this might help.
Dates of Manufacture* for:
Savage 1895/1899/99.
. Our database contains values of serial numbers through 566,000 which ended the year 1950. Serials did not strictly run sequentially. Therefore, dates may be a year different, especially near the "boundaries".
Enter the serial number (leave out the "," or ".") of your Savage 1895/1899/99 in the box below:

American Rifleman (July, 1980; page 28) contains a very different set of dates for serial numbers through 193000.
Enter the serial number (leave out the "," or ".") of your Savage 1895/1899 in the box below:


Lever Boss Codes: A = 1949
B = 1950
C = 1951
D = 1952
E = 1953
F = 1954
G = 1955
H = 1956
I = 1957
J = 1958
K = 1959
L = 1960 M = 1961
N = 1962
P = 1963
R = 1964
S = 1965
T = 1966
U = 1967
V = 1968
W = 1969
X = 1970

Savage 1895 1899 99 Dates of Manufacture

year of manufacture savage 99

1939 year of manufacture
.300 savage rounds are what you are looking for

Your Savage mod. 99 was built in 1941.

My guess is a 1968.

An example is here. You must use "300 Savage" or "300 Sav" only! Great ammo for deer. http://www.ableammo.com/catalog/cheap-savage-centerfire-rifle-ammo-sale-online-discount-prices-c-10480_14658_14743_14905_14822.html