Crojac,
In the past I have gone through Dallas. I thought about doing what you are thinking about. Personally I would much rather deal with the gun situation one time. "In Santiago"
If you have your guns off loaded at Dallas. I suspect that you will need to go outside security. This would mean doing the TSA gun check all over again. Keep in mind the flight from Dallas to Santiago is an American flight/plane even if your tickets say it's a LAN flight. Your LAN flight will be the Santiago to Cordoba leg.
The way I described worked well last year. After going through both Buenos Aires & Santiago. I much prefer Santiago, at least there you don't have to switch airports like you do in BA.
Yes 4.75 hours is plenty of time to get things sewed up in Santiago.
