That an L46-5, not an L66.
L46-5 on the left and an L66 on the right - notice the blade swedge differences
Also, the L46-5 has a 4-3/4" to 5.0" blade (slight variations by year) and the L66 sports a 4-1/2" blade.
View attachment 583131 View attachment 583132
The L46-5 was made from about 1947 or 1948 until 1973 or 1974. It is not in the group display of all Westerns knives in the 1975 marketing brochure.
Prior to WW2, the model number was G46-5 (there was also the G46-4 and the G46-6) and the knife had the "old style" mushroom shaped pommel of the 20s-30s that preceded the "modern bird beak" pommel. Western introduced the bird beak pommel style in 1931 on the Model 248.
During WW2, the G46-6 and G46-5 were made using the bird beak pommel in aluminum and brown swirl plastic with steel or brown swirl plastic guards.
BY CONVENTIONAL THOUGHT.... With that stamp, there are 4 options -
If the knife has a patent number as part of the stamp, then the knife is from 1946/7 to 1952 (maybe to 1955 - more below).
If it does not have either a reference to the patent or a model number stamped on the pile side of on the guard, then the knife is maybe/allegedly from 1952 to 1955.
If the model number is on the pile side of the knife, it is from 1955 to 1967.
If the model number is on the guard, it is from 1968 to 1973.
Per Western President/CEO in his 1977 book "The Knife Makers Who Went West", he states that reference to the patent was dropped in 1952 and that model numbers were added to the knives in 1955. I took this as gospel until a few knives popped up with both the patent number and a model numbed stamped on the ricassos.
A 1965 L46-5 was my first fixed blade, given to me by my grandfather when I was 10 y.o.
It is not any newer than 1973 because that is the year that BOULDER COLO was dropped from Western ricasso stamps on fixed blades. Don't know when it was dropped from folders, but probably about the same time frame.