I think you made a good choice on the barrel. I built my
404J with a Krieger 1:16" standard twist and it shoots the
Woodleigh/Hawk/Barnes bullets just fine.
I used a #19 contour and my rifle ended up at 10lb 4oz.
The #5 would have been a better choice. No point in
dragging extra iron around. Stock up on Varget and you
will be good to go.
Good Hunting
Raff