Before I ordered my XLR, I did give the .450 considerable thot.
I ended up with the same thots that GG stated, will I be able to buy brass 10 years from now? I did buy the XLR in .45-70.
Love the gun, and I probably woulda loved it just as well if it had been a .450, but I honestly feel that the .45-70 will be around for nother 125 years, and I don't believe that we can say the same for the .450.
Marlin has always made a fine firearm, however, thier specific designed cartridges have not had good record to success.