I had this exact problem with my son. He's 11 now and hes shot 100s of rounds and two deer with his 243. He has a standard hunting load with 100 grain soft points, and plinking ammo which gave a point of impact very near his hunting load at 100 yards. I use lightweight varmageddon bullets from Nosler's shooter's proshop and 15 grains of Trailboss powder. Theres nearly no recoil, enough terminal performance to blow up water jugs, and my boy gets lots of trigger time with his hunting rifle without abuse. My cost is about $5 per box of 20 rounds and I dont think you could wear out brass with that load. I'll be putting together a similar recipe for a .270 for youth elk next season