A finished render from a tutorial of Andrew Price… i don’t like too much it… i think is not so realistic! :no:
All done in Blender
Quite nice … but the very bright speckles in the center really kill the realism 
Not bad, but i find the image too dark. And the grenade too dark.
And if it is thrown I guess the pin should be pulled?
Ah, more finished tutorial work.
But that is actually a flaw in the tutorial… But throwing the grenade with the pin still in, I guess it could be considered a non-lethal weapon and those are popular these days… 
(it won’t kill you but it’ll give you a nasty bump on the head :D)