There shouldnt be any problem dropping a round in the chamber in a Mauser action, unless its a military action that hasnt been modified. The "controlled feed" doesnt by nature preclude the extractor being able to snap over a cartridge rim, the military guns just weren't done that way.
Wrong. It is tight because it is not meant to be loaded like that.
It will eventually break the extractor. Modify all you want but if you shave a bit off it you are reducing it's effectiveness... it's an extractor and needs that purchase. If you want to single feed that's fine... just click it into the mag and let the bolt do what it is supposed to do... control the round being fed
. The bolt face on a CRF is minus the walls purely for this reason. It's a beautiful thing to watch.