First post here, but it is important to use powders that generate full ballistics and that usually comes from powders that mostly fill the case. N550 has a burning rate between H 4350 and Win 760 which chronograph very close velocities in the .460 case with the same charge weights.
That velocity of 2487fps is way less than the maximum velocity for 500's but using either 760 or H4350 with 115grains will yield 2500fps in a Weatherby chambered rifle.
If the N550 powder is rated accurately, and they will likely vary batch to batch, that 115grain charge will be fine. I'd recommend starting a little lower if this is a new and unfamiliar rifle with around 110-112 grains to get aquainted with the powder, bullet and load.
2500fps is an accuracy node with 500 grain bullets but 150fps+, lower than the potential of the cartridge. Using H4350, I have loaded up to 123 grains for close to 2700 fps but that is a lot of kinetic energy and is taxing to poorly designed bullets causing excessive expansion and reducing pentration on larger animals.
I recommend looking for an alround heavy load for big bears moose and African dangerous game using homogenous copper bullets of 400-450 grains as the recoil is reduced and surprising accuracy is maintained. The faster IMR 4064, Rel 15 and Varget work best with these lighter weights.
Cloverleaf groups are very common with this cartridge and I have put 5 into .6 MOA to verify accuracy.
Always use a Federal 215 primer as it was created for this cartridge. Good luck with it and don't be afraid to ask more questions.