6.5x55 for the win. Utterly versatile- load it down for a youngster's sensibilities, load it hot for yours. Bullet weights and styles encompass a broader range than the .25. Fix him up with one and he'll be set for life. (Spoken as someone who was, and is, a huge fanboy of the .257 Roberts but who is an even bigger fanboy of the 6.5x55.)

"You can lead a man to logic, but you cannot make him think." Joe Harz
"Always certain, often right." Keith McCafferty