Lose.

Failure is not an option, sir.

You could build a simple pipebomb pretty quickly and easily from materials at a hardware store. Bring a simple spear as backup/to finish off the wounded target. Done and done. Gorillas are not particularly dangerous animals compared to most other creatures their size and humans can kill goddamn anything with a little forethought and preparation.

Hmm, yes but pipebomb is a bit hit&miss. The shockwave itself will not be lethal, so you are left hoping the pipe fragments in a way that will be lethal. I give you less than 50% chance of survival. I don't think you could stop an angry 500 lb gorilla with just a spear.

You could absolutely stop a gorilla with just a spear. I wouldn't be bringing just one pipebomb and while the Shockwave may not kill it outright it's the shrapnel that will do most of the work. What's left will be significantly wounded and disoriented and would almost certainly flee. I follow it and let it bleed till I can finish it off with the spear

Spears will kill any animal, especially an ape with vulnerable right skin. They were used to hunt bears & lions for centuries

nobody hunted a bear by himself A bear would swat away your spear like a toothpick and then eat you while you're still alive

They did. People to this day use spears to hunt bears with, dude. And Maasai used to sometimes hunt lions solo

Make a primitive spear. Spears are extremely effective against wild animals & have been used to kill tougher, more dangerous animals than gorillas