Had the house roughed in and found out too late that many of the studs were warped (bowed). What I did was replace those that were more than 3/8 inch out with straight ones. Used a hacksaw to cut the nails on the top and bottom, removed the bad stud, and toenailed in the straight ones. For the ones less than 3/8 inch out I used a hand plane to remove material if they were bowed out, ( a power plane would have been great, but being young and having more endurance than money I used a hand plane) If the stud was bowed in, I used strips of 90 lb roll roofing to build up the surface. A six foot straight edge to get the lay of the wall came in handy. Good Luck! Dodgeman