A guy on gunbroker sells 52cal conicals in a few weights that are lighter than the Parkers. The 52cal is a bit specialized but it does what it was designed to do very well. Sabots are limited but you dont have to experiment with which ones fit your bore.

My favorite load is the 325gr FTX over 130grV of BH209. Its barking on the heals of my smokeless Savage load. Granted i don't push my smokeless load to the max but it isnt needed with that bullet. Recoil gets a bit brutal with the max the Savage can handle. Its starts getting pretty close to a 458 WinMag or .404 Jefferys recoil levels.