I'm considering flying into IAD to then go overseas via British Airways. I'm curious about flying in on DL and then connecting to BA. How much hassle will I have in terms of my luggage? I doubt I'll be able to check through out of Milwaukee all the way to my final destination.

So if I have to go get my bags at the main terminal and then recheck with BA, that could be a grand hassle. Any input or suggestions are welcomed.

Also, what about returning back to the US. What can I expect relative to customs and then continuing on via DL to Milwaukee?