I have seen old 30-06 from 1918 a few before. very few in the 20s and 30s but many in the forties, most in the 40s are den42 and then later 44, 46 etc.
I just came across a few SL 43. I don't ever recall a 43 date on any ammo . the rounds are in good shape and have a " button" type primer. and a very light crimp. Primer is rounded not flat like most
anyone ever seen them ?