Remington and UMC merged somewhere around 1911. In the 1930s, DuPont bought a 60% interest in Remington. DuPont sold that majority share around 1992. Most ammunition made during the DuPont era has their logo on it. Ammunition has been made in Lonoke since 1969.
The 4 boxes of UMC I have all have a circle on the white end flap with "95" or "97" in the center with a light strike on the numbers (1-12) making the outside edge of the circle. That circle may only be the date of the box design, but it may also be the production date.