Lynn & Lloyd, 
Howdy stranger's......... 
 I just got my SBHH and I ran some of my .429 sized rounds through it. Not real promising at 100yds, but the gun is scoped with a 2X, so we'll see. 
As I mentioned before at Handloads, I usually slug everything (chamber & bore) first, but I had loaded ammo & was earger to shoot the gun, so out I went. 
After a nice long shoot & a thorough cleaning, I decided to take the time and check the chambers using a few unsized & sized bullets. I found that the chambers ranged from .4305-.431 The bullets that were sized in a .429 die, were actually measuring closer to .430. 
Do I buy a .430 sizing die, hoping for .431, or go straight to the .431 hoping for the same ?
Yeah, I know....buy both.....I will :-D 
The bullets would slide in comfortably and you could wobble them very slightly, so I knew I needed them fatter. Not much, but a little more.
Funny thing is that these .429 bullets shoot decent out of my scoped Redhawk, and the chambers are about the same as the Super. 
Take care, 
Bob