A boat tail hollow point bullet
is a match grade bullet design
that uses the concept of a teardrop like shape to give it a lower drag coefficient
and make it produce less turbulence
in its wake. Only the base of the bullet has a boat tail like shape, the ogive
is still pointed, it can also have an open tip
for even better accuracy at long ranges.
Conventional bullet design usually make use of a flat or even concave base which creates turbulence and hence affects accuracy. The effect is not much really but when you are sniping at ranges of excess of 500 yards you need all the help you can get.
Read also The Hague Convention of 1899.