Depends if the picture rail is purely decorative or if it's going to be use to hang things.
Personally I would at a minimum use a grab adhesive such as sticks like sh*t and 16g nails from a 2nd fix nail gun. Gold standard would be grab adhesive and countersunk then filled screws (use plugs if the final finish is raw wood and filler if it's going to be a painted finish).
Depends if the picture rail is purely decorative or if it's going to be use to hang things.
Personally I would at a minimum use a grab adhesive such as sticks like sh*t and 16g nails from a 2nd fix nail gun. Gold standard would be grab adhesive and countersunk then filled screws (use plugs if the final finish is raw wood and filler if it's going to be a painted finish).