The current Nosler and Hornady manuals give no loads for .243 deer bullets and VV powder.
They both say around 41.5 gr of 4831 or 7828, or 40.0 gr of 4350 is their accuracy loads, so 41.0 of N-160 is probably a good load to work up to.
Berger says 41.0 to 42.0 of N-160 for their similar bullet.