Carry as much as you can.
Bingo. You are allowed 11.2lb and that's what you should take. Why not? it's like in the flying business, ammo left home is like runway behind you or altitude above you. Either one is not much help
That includes the separate case with TSA locks. Buy the hard case, foam, and 60 rounds for each rifle. Put all on a scale and see what it weighs. If over limit, taks out a box of ammo from the spare rifle. Use the foam to keep ammo from moving around in the lockable case. This is not difficult!
