When I was searching for a big bore levergun to play with, I was looking for a cartridge that had "potential" for further "power modification". After a lot of study and research, I found that only the 444 in the Marlin levergun had the "potential" to achieve my goals. In factory form, the 444 is a superb cartridge ballistically for any North American game animal, and just about any African game animal as well (within its range).....in "modified" form, the 444 will take anything that walks the earth. My modified 444 has produced the ballistics of the 450-400 Nitro Express and 404 Jeffery (a 405 grain bullet at 2150+ fps for 4100+ ft lbs).....and that is not a top end load!!! There is no other factory produced levergun chambered in any of the other factory produced big bore levergun cartridges that can achieve those ballistic numbers.....and, if there is, somebody aint talking!!! After a number of years of working with the 444 Marlin cartridge in the Marlin 444 levergun, be it stock or modified, it would still be my number one big bore levergun/cartridge choice! "Heritage" wont get the job done ......the 444 Marlin will! ;D