If using screw in tips, 100 is popular...because with the total weight of the insert, the front end of the arrow really has about 115 grains total up front. With a target nibb, you will find a lot of guys (like me) shooting 120+ grains. Heavy tipped target arrows help reduce the stiffness of a target shaft, and also help reduce the effect of glance offs when you hit one of those stupid pin nocks and bushings.