RE: synthetic vs wood
If you take your rifle apart and seal the inside of the stock with a few coats of polyurethane then put a coat of turtle wax on the entire rifle, you will never have a severe problem with warpage unless you drop your rifle in a lake or leave it out in the rain overnight. I hunted last season in two days of pouring rain with my old walnut stocked rem 700 then took it to the range a few days later to shoot up my leftover ammo and it held its zero. Of course, every rifle is different.