Davec2,
I too have made a tool like your top one, the only part I would change on mine is the length of the bushing. I found the you can still get "misalignment" with the shorter bushing................[2" in length would make a great pilot]..........but to hard to make.
I did two barrels with mine, they turned out OK, but,..........I prefer the big Radius as a crown. If you do it right, you get a radius and a taper.