FlyerTalk Evangelist
Join Date: Nov 2009
Location: Northeast Kansas | Colorado Native
Programs: Amex Gold/Plat, UA *G, Hyatt Globalist, Marriott LT Gold, NEXUS, TSA Disparager Unobtanium
Posts: 21,653
You'll have no problems doing this. I've flown with my handgun on UA several times this year, and 15+ times last year. It's always inside a padlocked pelican case, which is inside of my soft sided rollerboard..
Just ensure that the mags are unloaded and any ammo you bring along is in the factory case, or something designed to store it. 9/10 times you won't have a problem with them wanting to see the ammo, but if you don't have it stored properly and get an agent who checks it, you may have some problems.
Just like US, make sure to declare it at check-in and then do whatever the process is for that airport w/ TSA.