I walk in with my rifle attached to the ball head. I see coyotes in the field when we are walking in often enough that I prefer to be ready without fiddling with mounting the rifle when I am looking at a coyote.
I use a RRS Anvil 30 and a RRS BH55. Both of these ball heads accept either a picatinny rail or Arca Swiss. Both heads use a lever clamp. They are very secure.
One tip that I will pass on is to keep the pan lock on the ball head loose enough that the rifle can swivel while you are carrying it. Otherwise a heavy rifle can unscrew the ball head a little bit if it swivels counter clockwise. If that happens the ball head will be wobbly on the tripod. The Avil 30 has several screws that mount it rather that 1 screw so loosening up is not an issue with the Anvil.
Photos of the Anvil 30 and BH55;
