The 450 Marlin is not a cartridge that is proprietary to Marlin. Browning makes a BLR that is chambered for it. In actual fact, Marlin itself has not made 1895 rifles chambered for the 450 Marlin for several years.
I have a BLR chambered for that cartridge and love it. In the BLR, because it does not have a tubular magazine, you can theoretically use pointy bullets, such as those designed for the 458 SOCOM. I think it might require removal of the magazine spacer.