If you are asking about the Winchester “white box” 125s those are designed for target practice. As already mentioned, the Barnes Tac-Tx(vortec) in 110 and 120gr are the gold standard for supersonic .300blk ammo off the shelf. There’s never enough of it so when you find it available you ought to grab a box or three and just have it on hand for when it’s needed. S&B makes a blue-tipped 120 that I like as well.
Where the white box will shine is for plinking and for dialing in an optic. Use the cheap stuff to get on paper and zero then confirm with your hunting ammo of choice.