Why would you want to? It will do all that the .450 will and if reloaded give it some more.I dont think it can be rechambered if you just have to do it.I really looked hard at the.450 before I bought my 45/70 's(i have two of them) But I just couldnt see its advantage at the time.
i don't reload. the 450 marlin has better factory ammo ballistics. i like the new nef/h&r break action with the thumbhole stock in 45-70. therefore that is why i was thinking get the 45-70 and have rechambered to 450 marlin.