Rick, I have the SAVAGE MODEL 99 stamp starting later around 28x,000. 285k-286k matches with other changes that happened.
*) <= 229,976 has receiver ring blank
*) 232,129 - 236,833 has receiver ring SAVAGE 1899 MODEL
*) 237,xxx is the oddball and is in the midst of a 12,000 number gap
*) 249,671 - 280,016 is SAVAGE 1899 MODEL
*) >= 286,587 is SAVAGE MODEL 99