Remington box code

I have a Remington 45 Automatic box with this code on back
Y 08 L
What is the date?
Green and white 50 round box.

Bob, is this a R397A box? If so, then it dates from 1940 (British contract).

Regards,

Fede

Box in question has the R397A code on front.
Picture of 2 identical boxes with R397A code on front.
One has the Y 08 L stamp on back.
One has IO JU1N 40 Lot 12 on back.

For whatever it’s worth I have one of these with a Y 06 L code on the back.

My sample of this box appears to be marked Y01 D. Since it has not been mentioned yet, I will add that the cartridge is brass-case with a narrow, knurled cannelure, a copper primer cup with what appears to be a dark purple primer seal (it lookd black with the “naked” eye) and a GM FMJ RN bullet.

John Moss

All boxes mentioned having a “Y” code date from the first half of 1940 (January to June). I also have an example dated “Y 19 E”.