put water into your mouth
look up open your mouth so that the water doens't spill out and insert the barrel into your mouth, and yeah, I really mean deap throat that shit
close your mouth around the barrel
pointe the gun sligthely up in reference to your jaw like in pic
>>11939536pull the trigger
the bullet should damage your brain, brain stem, atlas thus already having 3 pretty save ways of killing you instantly
furthermore the water catches alot of the kinetic energy of the gasses exiting the barrel which damages the whole frontal region of the skull and more importantly the neck with its arteries
should be quite a safe way but also a very disfiguring way of going.
I'd suggest putting a metal pot behind your head such that all of you remainings of the skull are somewhat cought and not splattered all around
and maybe even put your skull and pot into a big trash bag such that leakage is down to a minimum
hopefully you carefully considered anheroing and if so, well
good bye