How do you beat red dead redemption?

I was having the same problem for a while. But the answer is very simple and can even be as simple as common sense. First make sure you are using the left stick instead of the right. I noticed on about my fifth time trying the mission that I had been using the right stick the whole time. Next, use slight nudges of the stick. Don't push the stick all the way one way or another at any time. That's an easy way to get thrown off.

Hope that helps.