You should be able to C4 the tank without killing yourself. If you're able to get up to the tank and throw C4 on it, you should be able to exfiltrate and detonate at a safe distance. Suiciding, unless you absolutely have to is hella scrubby.
The hit detection is finicky. Sometimes you'll oneshot a guy down an alley other times you'll see blood splatter but not even get a hitmarker. In general, though, it's so good you'll feel kind of guilty using it. It's perfect in close quarters, especially in building, where you can get the kill even against a guy who shot first.
At the very least, it's better than the 40mm grenade 85% of the time. That thing really has two purposes: making doors and killing wounded people who have run around a corner. (most of the time you'll kill those people anyway from the crappy hit detection and lag) The grenade has a bigger one hit kill radius if you use the explosive damage spec, but if you do that you might as get "Mega****" tattooed on your forehead because you are a mega****.
:master::master::master: