This answer is an approximation. Assuming the lethal meteorite strikes its victim with the equivalent kinetic energy of a bullet. A bullet will have a velocity of about 300 m/s, while meteors can have velocities up to 50 km/s.
Taking the upper bound for the velocity of meteorites of 50 km/s, this means a 'meteor bullet' will have 27,777.78 times the kinetic energy per unit mass.
Now taking this value it is possible to estimate the mass of the lethal bolide. of course, there is a range of masses for bullets.
Depending on the gun, the mass of a bullet usually ranges between 0.02
kilograms and 0.04 kilograms. The mass of a bullet depends on the
caliber and type of gun used.
There is this caveat on the mass of bullets.
A bullet can be no more than 0.02 to 0.4 kilograms. Otherwise its ability to glide through the air would be halted. It wouldn't be the right size to pierce through anyone's skin or cut through a block of wood without the correct mass.
However, this mass limit might be overcome by the meteorite's velocity and its attendant kinetic energy. Also, it is probable that the meteorite's velocity will be reduced by its passage through the atmosphere.
This suggests a possible minute meteoric missile which can have the equivalent power of a bullet of a given mass and carrying its equivalent kinetic energy. This is complicated by the range of masses of bullets.
This answer is for guidance, but should provide sufficient information to devise a suitable lethal 'meteor bullet'.