I have a 28 inch McGowen with a 1/8 twist that I am shooting 140 grain Hornady BTHP at 2890 using 43.5 grains of IMR 4350. This is a max load for my rifle. I am not able to get the speeds that I see posted without excessive pressure. With my current load I am shooting in the low 4's so I am ok without any increase in speed but my question is:

I see that most are shooting H4350 and not IRM4350 is there that much advantage in the Hodgen over the IMR? Is it worth even looking into?