Regardless of weight 5Bs aren't designed for concert snare drum playing. The sound is too thin and good rolls are much harder to achieve than with a properly balanced stick. Firth makes and SD1 Jr, but for me SD1 is the go to standard for a 6th grader. By 8th grade they may be ready to invest in a pair of Coopermans or a more premium snare stick like the Ted Atkatz model.