1st off, I would find a different bullet for the .50.
If you are thinking of large game, we found maxi-balls next to useless on moose. They would not go in a straight line
after impact and instead of expanding, the front end collapsed into the huge grease groove behind it. This is also likely
why they deviated from going in a straight line.(along with the 48" twist bls. the boys were using.
The RCBS 450gr. or a similar bullet would be my choice.
The NOE 404gr. looks promising, as does the RCBS 340gr. from Buffalo Arms.
https://www.buffaloarms.com/500-50-340-swc-340-grn-rcbs-bullet-mould-rcb82087