Could be trying too hard on the third shot letting the round warm in the hot chamber and causing a little extra juice throwing the bullet off its node.Quite common on a sportier weight barrel especially if you are in a small node or at the edge of a node.
Never seen it happen with a three round group but that may be because I shoot five shot groups at least?

Just messin with you guys,its probabably the bedding

Last edited by SawDoctor; 12/14/14.