How about an AEA Element Max in .457? This is mine in .510, but the .457 is identical. Weighs just under 7# as it sits with the Leupold VX3 1.5x5, 36.5" long, shoots in the 475 - 500 ft-lb range (.457 may be slightly less FPE), and after sighting in will shoot 3 untethered shots less than 1"...