RE: Any have problems with Powerbelts like this??
I think eldeguello is right on with his assessment. About your only choice to make these bullets work for you probably is to slow the round down by either switching to the heavier 348gr version or by reducing your powder charge to the 80 to 90gr level.
I've had impressive results with the 348gr aerotips out of my Knight, but the Lead HPs give me the same headache you describe. I still have about 15 of the little devils and 1 day I'll give it a go on figuring them out - just haven't done it yet.
Lonewolf also gives good advice. PR's QT bullets in 350gr have become my round of choice these days and I keep the Aerotips on-hand in case a quick 2nd shot is required when hunting (as they are very convienent without having to use a bullet starter).
"Every moving thing that liveth, I give unto you as meat" (Gen 9:3)
Trust God..........but keep your powder dry!