Where's the tutorial? All this video shows is you getting a double kill with a grenade and then getting shot by a head glitchig camper that you then kill with a grenade. Point is, you already knew he was there and you died before you killed him so it's not really a solution.
How do you throw grenade at the glitchers on Raid where your grenade will just roll away?
Semtex does not roll away.
Throwing the grenade and killing him IS the tutorial.
If he would have shot someone else I would have still been able to tell where he was at.
Or even thrown a grenade at that area just to be sure. Reason I got killed was I was going after the guy behind the tank.
You will also notice I said I added the window kill in there for fun.
Simplest way is, in addition to what drewish said above, memorizing the invincible cover locations and aiming at headshot height.
The two perhaps worst cover spots to try to shoot people are the Round knob on hijacked at the corner near the outerwalkway up from the stairs bottom side, and the cardboard boxes you fought at in the 2nd part of your video.
However, both are easy to kill the enemy with the right weapon and aim.
Here are some weapons to use that will demolish people using cover if you know how to preaim for quick headshots:
Rockets can work sometimes, as can Grenade launcher. Crossbow with the 3way attachment works well too. However these depend on the environment around the cover spot.
If you weapon is not on that list...I would suggest not trying to kill someone from a distance who is behind cover, as they will always have an advantage due to your recoil problems. You can still try, but it will be risky even with preaim if you use a different weapon.
Never EVER, try to preaim with SMGS. Only the chicom might be able to headshot them before they kill you.
I generally find that people who complain about "headglitchers" don't tend to use any of these weapons, or merely are camper-style players who can use cover to kill people, but have crap reaction and thus cannot kill people who use the same cover in turn.