I just got number of emails asking the solution of level 4 and level 8, thus, i decided to share the solution of these levels on this blog :
Sniper Action : Level 4 Solution
In Level 4, one have to shot at the bottom of the pole and the pole comes down.
Sniper Action : Level 8 Solution
In Level 8, one have to shoot two bullets at the location shown in the image below.
Sajid Ali Anjum