What do you mean "Hold them back and then push them forward?" You mean when a man is holding a gun but just keeping it close to him at the ready and then when he sees a threat, he pushes it forward to aim?

like close to body, barrel up, then to fire, they push forward and out, like there slinging out rounds, then bring the gun back in close and do the same again.

Can you give me an example?

Wait, you mean hold with both hands and then pull the gun back so that the gun is almost touching your chest and then pushing it back out? That's just a method of having your gun at the ready. The pushing out is just so you can aim and shoot.

guess id have to find a clip, think of like in the old westerns where somebody behind cover is like flicking the gun over it to shoot.

Can you describe it in detail?

flick your hand like your throwing a dart, but imagine your shooting a gun. its common in older movies.

Who knows. Maybe it's for dramatic sake?