The terms are not related. Sptizer refers to the bullet's point and Boat tail referes to the bullet's base. A "spitzer" is a pointed bullet as compared with bullets with round noses or flat points.
Boattail refers to the base of the bullet. A boat tailed bullet is one that has a tapered base. That is to say, the diameter of the bullet base is slighlty smaller than the diameter of the bullet at its widest point.
Flat base bullets are those in which the bullet sides come straight down, like a water glass or a beverage can.
Boat tail bullets were designed for extreme long range shooting. The tapered base reduces the amount of drag and the bullet retains veolcity at long ranges better than the flat based bullets. Boat tailed bullets do not produce as tight a gas seal at the base of the bullet as flat based bullets and I have read that the use of boat tails increases throat errosion over time. Boat tailed bullets are longer than flat based bullets in the same weight and caliber and sometimes this will influence their use in a given rifle.
If you review ballistics tables, you will see that the difference between the two bullets in practical hunting terms is almost too small to measure. However, virtually all match target bullets are boattails.
Whether you use one or the other is largely a matter of individual preference and performance in your individual rifle. There are fanatical devotees to each one, but for hunting the difference is not worth the argument. Try both and use the one that shoots best in your rifle or the one that you like the best. You will find that most premium hunting bullets are flat based rather than boat tailed. Nosler Partition, Swift A-Frame, Hawk and most Barnes bullets are flat based. However, Nosler's Ballistic Tips, Swift's Scirrico and many of Barnes X bullets are boattails.
