Set a wire rack inside a large, rimmed baking sheet. Pat the turkey completely dry with paper towels and place it on the rack.
Sprinkle the dry brine all over the outside of the turkey. Use about half for the breast side and the rest for the back, legs, and wings. Gently rub it into the skin.
Cover the turkey loosely with plastic wrap or place it in a large brining bag. Refrigerate for at least 8 hours, or preferably up to 24 hours.
Remove the turkey from the refrigerator. Unwrap it and rinse it thoroughly inside and out with cold water to remove all the brine. Pat the entire surface and cavity completely dry with paper towels.
Let the turkey sit at room temperature for 1 hour to take the chill off. Position a rack in the lower third of your oven and preheat to 400°F (200°C).
Place the turkey, breast-side up, on a roasting rack set inside a large roasting pan. Put it in the oven and roast for 30 minutes.
Reduce the oven temperature to 325°F (165°C). Brush the turkey all over with some of the melted butter.
Continue roasting, brushing the turkey with melted butter and any pan drippings every 30-45 minutes. Roast for an additional 2.5 to 3 hours.
The turkey is done when an instant-read thermometer inserted into the thickest part of the breast and thigh (avoiding bone) registers 165°F (74°C). If the skin darkens too quickly, tent the breast area loosely with aluminum foil.
Carefully transfer the turkey to a large carving board. Let it rest for 20 to 30 minutes before carving and serving.