The walking bullets are prolly caused by improper bedding or the stock, or the fit of the stock.
If he's shooting deer a long range, he'll need a bullet that will expand properly on out there even when the bullet has slowed down. That's not what a "Partition" or other "Controlled Expansion"...
It should shoot right out of the box. I have never owned an accurate gun that didn't shoot well from the gitgo........... It might get slightly better though.