i called delta before i flew and they said no air tanks, so I didn't fly with my tank. they said the gun isn't a problem just tell the person at the counter. I didn't say anything to the person and everything still went smoothly.
Stupid delta. Fly jet blue. No problems with gear. Just put the tank seperate in your gear bag, make sure it's empty and your barrel is off the marker. Print out the letter from pspevents.com that Emily Mood wrote, just in case they have questions.
shipping your tanks via UPS or FedEx is a great idea. I don't know how much it costs but that's what our team has been doing. Have it shipped to your hotel. Just make sure you ship it early enough that it gets there in time for you to play.