My grandfather recently passed and left me some of his belongings. In one of the boxes I found a small cardboard box of shells that appear to be made entirely of brass. The box itself says No. 00 BUCKSHOT M19. The top or cap of each shell has 00 BUCK printed on it. The rim has REM-UMC No 12 BEST stamped into it. Any ideas where these may have come from, or when?