I've traveled with handgun ammunition several times and use recycled retail packaging -- the plastic tray and cardboard box that ammo comes in at the store. It's free, works well, and neither the airline representatives or the TSA have had problems with this approach. There is no need to put ammunition in any sort of lock box as must be done for handguns.
If you want to look at other options, the TSA points to 49 CFR Part 175 as far as what type of packaging is allowed:
"Small-arms ammunition for personal
use carried by a crewmember or
passenger in his baggage (excluding
carry-on baggage) if securely packed in
fiber, wood or metal boxes, or other
packagings specifically designed to
carry small amounts of ammunition."
As far as the amount of ammunition you can transport, that is up to the airline. Each airline I've flown with has stated 11 pounds -- including Alaska Air from Seattle to Boston. I see you live in Alaska and if you haven't flow Alaska Air outside of Alaska, you may not be aware that they effectively have two different sets of rules regarding luggage and they are very different. One set applies to flights between airports within Alaska. The other set applies to flights in and out of Alaska as well as flights which take place entirely out of Alaska. In general, the airline's rules for travel within Alaska are much less restrictive. It wouldn't surprise me at all if the airline's ammunition weight limit within Alaska was very different than flights into and out of Alaska.