Shallow groove bullets

[Digital Dan]

Wondering who among you has experience with shallow groove cast bullets? Say .010" groove depth or less. Read recently of a gent that used a bullet that was .001" less than barrel groove diameter with bullet groove depth equal to bore, this for BP shooting, and did so with great success in competition.

Thoughts/experiences appreciated.

[runfiverun]

450 isn't uncommon in a black powder 45-70 boolit size.
especially if it's been wrapped in paper.