Do you hunt with your Dad? if so why not a 7Mag? Then if both guns are sighted in with the same ammo you can interchange if one guy runs short.
Just a idea for you, you may want something completely different.
My Father and I both have a Winchester 88 in 308. On occasion we will both have the same guns that are using the same ammo and we can even interchange clips, ( or am Suppose to say magazines).