I also have a t3 in a 300 wsm
and it loves the 210 gr hornady bthp. Not as much as it liked the 178 a-max. But I am still MOA with them.
I am currently shooting 64.5 gr of RL 17 at 2950 fps, they do have alittle wack with them. my COAL is 2.90 they only just feed from the magizine.