the folks at Marlin say the 1895M is a slightly stronger frame than the 1895 4570, some thing to do with thread design and heat treating I believe. if the Winchester action is stronger than the Marlin it would surprise me . I have put some realy stout 450 Marlin hand load's through my 1895M and it has shown no sign's of failure yet. if I would ever need more power I would just grab my CZ 550 safari in .458 Lott cause if that can't do it I ain't going after it anyway. I do find it interesting that Garret cartrige says that thier heavy grain (540 grain i think) hammer head in 4570 sould ONLY be used in modern Marlin1895 lever actions . Garret makes some very hot ammo ,and you better have deep pockets because thet ain't shy about the price.that said they make some of the best ammo on the planet . I have both Winchester and Marlin lever rifles and to me the Marlin's just feel tighter and less floppy. upon lock up this may not matter though.