Some .500/.416 NE reloading data for comparison to other sources:

These are untested by me. Received by me from an email. From this thread on NE.

410 gr bullet
- powder H-4831 Min 94 grs Max 97 grs - Velocity 2270 fps
- powder H-1000 Min 97 grs Max 109.5 grs - Velocity 2380 fps
- powder IMR 7828 Min 96 grs Max +-99.5 grs - Starting load only suggested, untested load by originator
- powder IMR 4831 Min 91 grs Max +-94.5 grs - Starting load only suggested, untested load by originator
- powder AR-2214 Min 97 grs Max +-109 grs - Starting load only suggested, untested load by originator
- powder AR-2217 Min 96 grs Max +-99 grs - Starting load only suggested, untested load by originator

350 gr bullet
- powder H-4350 Min 94 grs Max 98 grs - Velocity 2540 fps
- powder H-4831 Min 98 grs Max +-103 grs - Starting load only suggested, untested load by originator
- powder H-1000 Min 104 grs Max +-109 grs - Starting load only suggested, untested load by originator
- powder IMR 7828 Min 100 grs Max +-103 grs - Starting load only suggested, untested load by originator
- powder IMR 4831 Min 95 grs Max +-98 grs - Starting load only suggested, untested load by originator
- powder AR-2214 Min 104 grs Max +-109 grs - Starting load only suggested, untested load by originator
- powder AR-2217 Min 103 grs Max +-103 grs - Starting load only suggested, untested load by originator