Answer:
There are four basic shapes.
1. Waddcutters, These are flat and used for target shooting.
2. Pointed, These are used for speed and distance.
3. Hollow point. These are used for hunting. They mushroom on impact.
4. Round. These are universal pellets.
There are variation of these shapes but these are the basic shapes.
Pellets come in various sizes for different boar air rifles.
.177, .20, .22, .25, 9mm, 45 Cal and 50 Cal.
The last four sizes can be found in PCP air rifles. (PreCharged Pneumatic) These are very high powered air rifles. They require 2000 to 3000 PSI to fire the rifle.