You're right, Suicide, I think you're a kid...
I suggest that after you pop up and shoot at the "nearest target" you keep your barrel pointed at that target, even though there is an obstacle between you and it. It is easier to move out of cover and shoot at it without having to get your barrel back at the same angle once you have changed that angle. If the barrel is still pointing in the same direction, the correction you need to make when you come out will be slight and you will do it quicker.
Also, try to come out of a different part of your obstacle... That way, if they are out and posted on you, they will have to keep adjusting their aim.
I suggest that after you pop up and shoot at the "nearest target" you keep your barrel pointed at that target, even though there is an obstacle between you and it. It is easier to move out of cover and shoot at it without having to get your barrel back at the same angle once you have changed that angle. If the barrel is still pointing in the same direction, the correction you need to make when you come out will be slight and you will do it quicker.
Also, try to come out of a different part of your obstacle... That way, if they are out and posted on you, they will have to keep adjusting their aim.