Mike I'm shooting a proven bullet for me. Its a .401" (10mm) 200 gr Hornady XTP. When I have more time to work with rhe rifle I'm going to try some full bore bullets. I ran a 250 gr Barnes .451" bullet down the bore and it felt snug but not overly tight. That could be a good start. I also have others i want to try.
you know how it works. Always trying to find the holy grail load.