Dating of WInchester boxes by lot number

I know about how to date Winchester and Western boxes from the lot number stamping, for the 1950s and later, but what’s the date deciphering method for earlier Winchester boxes?

Winchester is pretty easy

The first one or two digits are the month, and the next digit is the last digit of the year then a space followed by the day of the month.

126 30 = December 30, 1936 or 1946 or 1956 or etc…
80 23 = August 23, 1930 or 1940 or etc…

The box style and markings have to be used to decide the decade.

If the cartridge and box were marked Winchester but were actually loaded in East Alton by Western, then there is an A prefix on the code

Example: A41 22

Winchester converted to Western/Olin codes in 1957/1958

Western from 1928 (Year B) used a more complex code. The sequence was Year-Month-Day. The year and month were identified by letters and the day by a number, but with the order of the numerals reversed. This code is often proceeded by a number which is called the “packer #” which has nothing to do with the date.

The months are the letters A (Jan) through N (Dec) with I and J dropped out of the sequence.

3KE41 is May 14, 1935 (E=May, K=1935, 41=14 [numerals in reverse order in code])

This box code on the box in my collection was actually A3KE41 with the “A” indicating that it was produced at the Winchester plant

The year letters are as follows and continue to repeat
1928 B
1929 C
1930 D
1931 E
1932 F
1933 G
1934 H
1935 K
1936 L
1937 M
1938 N
1939 P
1940 R
1941 S
1942 T
1943 U
1944 V
1945 W
1946 X
1947 Y
1948 B

Hope this helps.


Edited 9 July 15 to correct error pointed out by xjda68 (Joe). Thanks Joe!

Thanks Lew. I knew the later W-W coding, but not the earlier one fro Winchester.

So, assuming they didn’t use “z” (Probably because it looks like a “2”), that means that 1928 and 1948 duplicate each other with the letter-code “B”, correct?

Edited to correct typo error in one date only, as Lew Curtis’ follow up to my question was correct in that the date I typed was a typo error on my part.

John, I think you meant 1928, and you are correct that 1928 and 1948 have the same year code. That is why you can’t just read the code, you have to look at the type of box it is applied to. Fortunately Western/Olin didn’t keep a box style for 20 years.

Winchester is harder because the number code repeats every 10 years.



I am a little confused.

You state:

“The first one or two digits are the month, and the next digit is the last digit of the year then a space followed by the day of the month.”

126 30 = December 30, 1933 or 1943 or 1953 or etc…”

12 out of the 126 would be December, I get that, but the 6 in the 126, how does the compute into 1933 or 1943 or 1953 or etc…??


Thanks Joe!

I’d like to say that you caught the deliberate error included to see if anyone read the post.

Sadly, that is not true. It is just a matter of old age and not paying attention to what I was writing. Thanks for catching the error.


End flap code 1SD81L
I get March 18th 2004. Would this be correct? This is a Winchester Wildcat 22 box from 1997 - 2009 era.


Edit: I simplified my question.

WEBMASTER- Some good info to pull out and post on the main site or the members site.