You are referring to the lock screw and peg just in front of the right hand lugway? This is the cam which kicks the bolthead over to start the locking process. I do not think that it has anything to do with the barrel, and is a bit of a distance from the breech face. The receiver has a step just in front of the main receiver ring, and the barrel screws up against this. I've never debarreled a 1910, but I don't think that the process is particularly different from any other bolt rifle. Square threads, and breech face cuts, which make machining up a new barrel a bit more interesting than some. To the best of my knowledge a 1910 barrel torques in a conventional manner. Need a good barrel vice, and a way of grabbing the receiver without damage. 1905 Rosses are just plain odd in their barrel attachment - a very coarse fast pitch left hand thread, the barrel being locked in place by a tangental set screw. It is sometimes possible to remove a 1905 barrel by hand, which was the intent.
