(8) Small arms ammunition for personal use carried by a crewmember or passenger in checked baggage only, if securely packed in boxes or other packagings specifically designed to carry small amounts of ammunition. Ammunition clips and magazines must also be securely boxed.
I am not saying you might not get away with it, I am saying that it can be a huge hassle to show up with a hand gun, two loaded mags, and a hard case only to have them interpret the legal reference differently than your reference. I have seen the law interpreted to mean no loaded mags and the ammo in an ammo box.
It was a hassle all right. 15 rounds of hollow-point confiscated.
I agonized over that ambiguity myself and ended up packing the weapon and two empty mags in the lockable pistol case. I took the cartridges and put them in a clear baggie so they could see what they were without having to handle them. No one even blinked other than to compliment me on my Colt Commander.