See below for actual BHN measurements:
Note that 1:10 will fall in the mid 8's.
Note also that pure lead-tin alloys will neither harden nor soften with age. Nor will they respond to quenching. They are what they are. Add antimony, however, and you have a whole different ball game.
Special note: Lyman#2 (5/5/90) is peculiar in that it also hits its BHN(~15) right away and stays there (mostly) irrespective of aging