dw, Thursday I sold a Model 7 Youth in 260 to a man who had his small 8th grader with him (would guess him at 70-80#s). Topped, with a 2x7x33 VX I Leupold it was a SWEET feeling rig. I also recommended 2 boxes of Rem 125 Nosler Parts for it, which they got. If ever a more perfect rig for small beginners that is priced VERY reasonably exists, I' ve not seen it. The recoil difference between a 125/260 vs 100/243 is non-existant. My old Vanguard 25/06 while not much in the recoil department, is more than I would recommend for kids under appx 12 and/or 120#s. Stay away from varmint/bull barrels for youngsters, its hard enough for them to properly hold a fullsized, normal weight rifle nevermind one that is an extra pound or two heavier toward the front. The Youth models in the Rem 700 ADL and Model 7 are AWFULLY hard to beat for the money. And if you have more than one child, they only make more sense as you can " hand them down" to the other kids as the oldest one ages (as is the case with my above mentioned customer and my own kids!). You can also add a simple replacement stock of full length to make it ready for anyone.
Now if you REALLY want to see slick and dont mind a lil more money, check out the Browning Abolt in 243 Win SuperShort Mag. I LOVE the feel of that lil gun and will probably get one for my oldest! Ballistically its closer to a 240 Wby Mag than a 243 Win.

RA