450 Marlin brass can not be easily made from any other brass. The belt is longer, front to back, than any other belted brass so if it becomes hard to find you will not be able to make from any other brass that has better availability. It is also not apt to become the basis for any other cartridge that will have great popularity. For those reasons, I would avoid it unless you can but 1000 NEW cases before getting the gun.
2120-September 1, 1945
To: D A MacArthur /C H Nimitz
From: H S Truman
Political Correctness is a doctrine, recently fostered by a delusional , illogical minority and promoted by a sick mainstream media, which holds forth the proposition that it is entirely possible to pick up a piece of cr*p by the clean end!
Now, with special thanks to the Truman Museum and Harry himself, you and I finally have a full understanding of what "POLITICAL CORRECTNESS" really means.....