I would call it "stout, but manageable". I've no experience with the 300WSM, but I don't think the 450M is as bad as my 338WM. Weight of the rifle definitely does affect the recoil. The recoil out of the 450M bolt I have is a lot more tame, but it weighs about 3 pounds more than the BLR. I also have the 450M in the Marlin Guide Gun and recoil from it is about the same as the BLR. I would think that a full-house 45-70 load from the NEF would be equivalent to the 450M out of the BLR or GG.