Chief's concerns are valid about cutting the chambers deeper, IMO. But, I will disagree that typical "long cones" do any wall thinning to be of concern. The typical "long cone" reamers available from reputable sources have an angle much steeper than the outside taper of the barrel. Therefore, the thinnest point will always be the corner at the front of the chamber where the forcing cone starts. Deepening chambers will reduce wall thickness at the already thinnest point.