Yes, i am still interested in this old project that has caused so many folks so many headaches.
Up to this point, I think i have at least a starting point in terms of component fit and safe powder charge.
Based upon this chart:
https://www.ballisticproducts.com/VP92%20data.pdf
I see 1&3/8oz lead (~615gr) in the VP ,now name changed,92 wads w 20-22gr Steel powder (1080-1180fps/9.9-11.6kpsi) or 23gr Blue Dot (1150/11.8) or 30gr Lil'gun (1220/10.9); there is a good place to start thinking.
If I use a .52 caliber ball, which will weigh 212gr each, for a total of 636gr. but properly alloyed which they would be to get BHN minimum 15-16; need them down to 205gr each; those fit snugly in the VP92 wads and have a nice but reasonable slip fit in my 20ga barrel.
next is figuring out how to prevent blown wads, which is THE problem according to all the stuff posted in the past by James Gates.
ideas?
Cardboard or rubber O-ring in bottom of wad? balls touching each other like the 12ga tri-ball? or have a seperator in between each ball like the Hevi-Shot Hog Wild balls(*)?
All ideas welcome.
And more later, i hope.
C-
(*) which, BTW, i am having analyzed and will report back here on what those balls are made of hopefully soon!