Enjoy. I have one as well and have had no issues using the 500 S&W RCBS dies for loading the JRH. I use cut down 500 S&W brass and have not run into the buckle issues but maybe I am just lucky. I run a 475gr hard cast over a generous portion of H110 and it is very accurate out to 100yards. Also have a practice load using TrailBoss that is very mild.

Have Fun!!