It seems to me that the 45/70 is able to get similar balistics but the large case does it with more reasonable presures.
It is also my guess that many of the marlin guide guns are sold to folks who don't really need the power , they just want to be the meanest SOB on the block (or at least own the meanest rifle). For this reason alone a lever gun in 500 or 460 would likely sell like hotcakes but it might kill the sales of the guide gun .I suppose if you were Marlin this wouldn't be a great buisness decision , if you were some other company it might be a good idea.
It is also my guess that many of the marlin guide guns are sold to folks who don't really need the power , they just want to be the meanest SOB on the block (or at least own the meanest rifle). For this reason alone a lever gun in 500 or 460 would likely sell like hotcakes but it might kill the sales of the guide gun .I suppose if you were Marlin this wouldn't be a great buisness decision , if you were some other company it might be a good idea.