Lucky Gunner has a post on things that are preventing you from beig a better shooter. It also suggests a performance & automaticity speculation table that has many different drills and standards on it.
http://www.luckygunner.com/lounge/why-you-arent-better/
And before you start to think about working on your gun to reach the goal, here is another comment from Daryl Holland on that.
http://soldiersystems.net/2016/05/14/gunfighter-moment-daryl-holland-15/
From: Lucky Gunner, Soldier Systems Daily