A 400 grain TSX has been made fairly recently. BUT, it is under an agreement/contract with Buffalo Bore Ammunition. It is loaded in their 458 Winchester. I think at one time they were planning on loading it in the 458 Lott also.Yea that’s interesting. I have 350, 450 and 500 grain .458 TSX but I’ve never seen a 400 grain. Seems odd.
I believe there is a similar agreement/contract regarding the 350 grain TSX FN that Buffalo Bore loads for its 45-70 ammo.
So neither are available across the counter.