First, be sure to follow all laws and regulations.

There is a big difference between video games and real life aiming - especially with iron sights.

Take the NRA Basic Pistol or NRA Basic Rifle. They will teach you firearm safety and proper shooting form. One that that is very important is determining your dominant eye. Here is a link to help determine which eye is dominant.

http://www.fieldandstream.com/blogs/...r-dominant-eye

You might also be trying to keep the rear sight, front sight and target in focus at the same time. Our eyes can only focus on one focal plane at a time. Focus on the front sight - the rear sight and target will be slightly blurry.