The .257 is a youth load.
I agree, but it is a Ruger ultra light 20". My 11 year old Grandson likes to shoot it but it is a little much for him. Thought I'd try some reduced loads for him.
Does it have a recoil pad, or does is still carry a factory butt place?
My first inclination would be toward a good recoil pad for the lad. Then as MD mentioned, H4895 is a kids best friend. I'd stick with a bullets that is know to perform well at the lower end of the velocity spectrum such as the 90/117 gr NBT.