I recall reading when the 450 first came out that Taurus did not recommend shooting hotter loads because the geometry of such a large caliber in such a small package made for a very thin-walled forcing cone. I also would recommend calling Taurus but I suspect they are going to recommend standard-pressure loads. On the other hand, I have read a number of tests on the 450 which listed velocities for Cor-Bon 200 grain loads which are listed at 1150 fps probably from a 4 inch barrel, so I guess it can take a certain amount of them anyway. Lazarus