Lawdog, I have been following this and your other thread on the medium bore forum rather closely for some new ideas. So I have to ask, why build a .450 Marlin on a standard length action? Why not just go with the .458 Win. Mag.? I'm asking because the idea of a bolt action .450 Marlin sounds intriguing, but seems like it is better suited to 400 grain bullets and a short action. I have a Win model 70 in .300 mag I bought for the action, and don't know what I'm going to do with it yet. I just know it's either going to be smaller than .30 caliber, or bigger than .375!