I was looking at the WINCHESTER LITTLE BIG HORN CENTENNIAL 1876-1976 44-40 AMMO and it brought some questions (I am a 44-40 freak). I noticed all of the boxes I could find on the net were coded LE which would be May 1976....of course right? Well, I also noticed a few that had flat primers rather than the "oval". So far the only days of production I can find are the 19th, 23rd and 25th. I also noticed that the hand-loading components "White Box" with the red W were produced from 1974 to 1977. Any idea if this was the transition from one primer design to the other? Prior to the mid 1970's, Winchester primers were "oval" rather than "flat" as they are today.
Also, about Pre-WWII, Winchester flip-flopped several times between oval and flat primers. The following was found in Vol.I of Dan Shuey's "W.R.A.Co. Headstamped Cartridges and Their Variations":
"When smokeless powder cartridges evolved in the mid 1890's, the No.'s 1 and 1 1/2 were adapted with a different formula. They were also marked with a form of "W" to denote for smokeless loadings. All of these primers used an oval-shaped cup until around 1900 when it was thought that a flat or pan-shaped cup would give better and more positive ignition. According to (George) Watrous, this thought and trial process was repeated several times for a number of years with the results being the same. After a period of use, the shape of the primer cup was always returned to the original oval shape because the results with the flat shape were unsatisfactory."