I’m looking at a red/white/yellow carton of Winchester Super Speed 30-06 Springfield. It is marked Division of Olin Industries which should date it between 1945 and 1954. The flap is marked A65 7. I assume that means loaded by Western June 7, 1945?. Another marked A72 25 would have been loaded July 25, 1952?
As I understand it, for Winchester ammunition, 1939 was the date when “Division of Western Cartridge Company” first appeared on the labels. In 1945 “Division of Olin Industries” appeared, and in 1954 "Division of Olin-Mathieson Chemical Corporation. In 1968 the dual designation Winchester-Western (W-W) appeared.
So, based on that, I would guess that your cartons, being a Western contract item, would date post 1968. The end flap codes would be different than those indicated by Lew.
What was the “1946 style box”? Maybe that is getting to the heart of my question. Are you saying the pre-1946 boxes were different? See my comment above re the red/white/yellow box apparantly from 1945, unless I read the code wrong.