I'm taking it that you have the programs needed to open up the RFAs of BF maps and also BC. So what you need to do is open the map in BC that you want to mod, use the material editor tool and makes the out side the map what ever material you want. Then save that map as a copy, name it what ever you like. That’s it now your out of bounds is gone (note, you will still see the red lines in the pic of the map in game, but you you will no longer die) I know you are saying "Thats way to easy", but that's all you have to do.
IF you are talking about doing this server side, like how it is on Mafia servers (well the last time I was on)…
Say you want to make Kursk completely open, do the same as I said above using the map Kursk and also this… AFTER you did above, You would open up Kursk to see all of the rfa files (using your RFA unpacking program) and look for the “materialmap.raw”, pull that file out and sit it on your desk top, now open your server side Kursk map and unpack it and find the materialmap.ra w and now take your new materialmap.ra w file from your desktop and put it in it’s place, build your new map and save is as a patch like this kursk_004.rfa (005, 006 and so on, what ever number would be next in line). Just a side note, With Windows servers it doesn’t matter if the name is Kursk_004.RFA, but with little old Linux, make sure that file looks like this kursk_004.rfa (Caps in Linux is a no no, wont hurt anything it just wont run your patch).
Now remember there still is "a end to the map", you just can't keep going and going. Most maps have a line you can see when that map ends. There is no way to stop from dieing crossing that line.
Hope that helps.
Edit... I think there is a way to get BC to make a patch for you, but that I don't know about. I have tried, but it has never worked for me.
