White Buffalo Shooting

[mazter]

Im in a Shooting Club & we are going to have White Buffalo Shoot's this spring & fall at the range. We are going to be using .22LR only shooting at a 8 x 10 Steel Buffalo 200 yards away, It will be a Timed shoot. I have some questions,

What is the best .22LR out of the box to use for this, Or would I be better off Building a Custom .22 ? If its Custom what would be best for this type of Shooting ?

Which ammo will be best for me to use at this range to knock it over for the score ?

Thanks for any info anyone may give me on this subject.

Mazter