Bevel based bullets are much easier for automated casting machine to cast bullets with fully filled out bases, and the bevel helps protect the base from shipping and handling damage. However,in some shooting disciplines like bullseye shooting, some competitors don't resize their cases at all, preferring to leave the case at it's fired dimensions for greater consistency in chambering and chamber alignment. Often, the shooter will simple bell the case mouth slightly and seat their bullet (commonly a bevel based wad cutter), which is also unsized, and of a slightly oversized diameter. This way the brass is worked less than normal, and the finished cartridge is really pretty consistent dimension wise. A slight taper crimp finishes everything off.