Magnum... yes, if you fell flat on your back, that wouldn't be a good thing. At least one holster maker doesn't make holsters for the small of the back for that reason. Of course, I can't recall ever falling on the flat of my back in my life, so I don't think that's very likely, but it isn't impossible. If I were a cop or something where I would quite likely be running with a gun on me, I surely wouldn't use this method of carry... I only do it for occasional, casual, joe-citizen carry.