I recently had a (empty) TSA case shipped to me, nearly half way across the states, and no problems. Wrapped in one layer of plastic, taped, and it arrived in near perfect condition.
However, working for a shipping company, I will go ahead and give some advice.
Fill all spaces in boxes, if there's room for it to shift, it will.
Use the appropriate size box. Not too big, not too small.
Orientation arrows when necessary.
Don't be afraid to pack around the shipped item, who knows how someone will handle your package once it leaves your sight.
Don't skimp on the tape. (One piece of tape WILL NOT hold 40 pounds)
Use your own judgement.
Best of luck!