[Zfurlong]

My guess would be it's the size of the bucking. Try reverting to the old bucking with all other new parts and try that. If still nothing, old barrel, new bucking, new parts, continue in that fashion until it works, then you'll have your answer. If none of that works, then start the process all over again with 2 old parts and all other new parts (my guess is either barrel or bucking though)