Slow is smooth - smooth is fast
Start slow, then the speed will come.
What are you trying to achieve ? If your trying to put all 6 center mast that's one thing, try using the concept of 'breaking the man down' which I feel is a very useful revolver tactic that seems to have been lost in the folds of time.
Try just 3 rounds at a time hip-gut-chest, I think you'll find the recoil raises the gun to a natural elevation after each shot. Learn that natural elevation for your gun and then apply it to the target.
I think by doing so you will develop a more combat effective tactic than trying to put all 6 in the chest.
How are you standing ? Weaver ? Break into a low crouch and pull 3, and I think you'll find the above to apply well.
Somebody let me know if I'm way off the mark
An old west lawman once said when asked why he carried a .45, "because they don't make a .46"
God created man, Sam Colt made them equal.