Semi - I don't think I will worry about JBing the bore right away. Those .535" balls were so tight even with the .015" patches that I got the ball stuck right away with the short starter. Then I had to literally pound it down with the palm of my hand with the long end of the starter. Then getting it down the bore to the charge was an other ordeal.
The .530s started with a solid rap and a hard steady pressure to seat them. I think they are just the right size.