I have been searching this site and the internet and I have not been able to find what I am looking for. I am having a .458 American built and I want to utilize the 450 grain Barnes triple shock X bullets; however, I have not been able to locate any load information for this. Most of the data pertains to the 45-70, .450 marlin, .458 win mag, etc. and the bullet weights seem to stop at the 400 grain level. I would appreciate any insight that you can offer. The intent would be for target shooting and hunting if that matters. Thanks in advance.