Forest's parting gift is an article in Resident Evil Recollections. It was uploaded on 10 December 2014.
Forest was friends with Chris and Jill since before S.T.A.R.S., and his marksmanship rivaled that of Chris, so much so that the pair would often compete for 1st place in shooting competitions.
He is eventually overcome at some point in the Mansion during Resident Evil, but at least he leaves behind his grenade launcher in Jill's scenario. The flame shells are particularly useful for burning zombies to stop them from mutating into Crimson Heads, and like me I'm sure most people saved up the flame shells precisely for this purpose.
Now if only Chris had a grenade launcher too...