we call small points "bird points"
not necassarily what they were used for way back in the day
alot of small "bird points" are found at known buffalo kill sites
by todays standards,and laws they wouldnt be good for large game
but i believe our ancestors used them for large game
to the best of my knowledge north america has little if any true flint
but alot of differant varieties of chert
both are knappable
but i could be wrong on both counts