Back when I flew w/ archery equipment, arrows were easily bent in any standard box and they fit awkwardly in hard side luggage.
I took a length of 4" schedule 40 pvc pipe and glued a cap on one end and a female drain out fitting on the other and then used a male fitting to cap it. Had a chunk of foam at the capped end to protect points.
For a "security" lock, I drilled a 1/2" hole through the pipe and female fitting, screwed in the male fitting, marked where holes the holes would line up and drilled a second set into two sides of the male fitting. I would run a 12" to 16" zip tie through both set of holes. TSA could easily cut the tie for physical inspection, which would also alert me if it was opened. I carried spare zip ties for the return trip.
For a handle, I sewed a piece of nylon strap to 2 medium dog collars with the adjustable plastic buckles. I had the dog collars adjusted to be fairly tight around the pipe. When the pipe came down the luggage carousel, I snapped the dog collars around the pipe (at 2 Sharpie lines on the pipe for a predetermined balance point) and carried it like a little suitcase.
Prior to TSA BS, I would just carry the pipe on as carry-on luggage, with as many as 36 32" arrows w/ points.
Depending on the sword, you might have to go up to 6" pipe depending on the width of any guard/quillons.
"...a buzzard's gotta eat just like worms." Josey Wales (1976 Clint Eastwood movie)
"A Folding Blade is a Bleeding Finger" - Zzyzzogeton
Beckerhead #346 KaBar Krew #17