All right you fucking faggots, here is the thing about suicide by gun:
Many people fail to do it properly and end up suffering for an hour or more.
First of all: choice of gun is important. While even a blank can crack your skull with ease and injure you brain sufficiently for some major braindamage, that's about it. Death won't follow immediately. Instead you will slowly bleed out. Sure, a round will rip a hole into your brain and cause lots of bleeding, but again, unless you do it right you will still bleed out on the floor slowly.
The hot gases from the muzzle also cauterize some of the bleeding near the entry, leaving only the exit wound sufficiently open for easy bleed out.
Chosing a caliber that will create a big exit wound, like .45 or even some shot is key if you don't know how to place your shot properly.
See pic related.
Putting the muzzle at the roof of your mouth will lead to a shot through the frontal lobe, or even the face. The frontal lobe is responsible for thought. You will instantly become a potato incapable of logical thought or emotional feelings. Pain and motor centers will still be alive and kicking, sending signals of immense pain in the top of your head and roof of your mouth, as well as nose and face area, because your brain actually doesn't have any pain sensors (which is why brain surgery can occur with a fully awake patient and local anesthetics only).
Placing the muzzle against the back of your throat is slightly better, but no prize either. You can either hit your Cerebellum, which is soley responsible for gross motor skills and automatisms (like tying your shoes) or you hit your brainstem, which regulates breathing and sends signals to your limbs. Hit that and you will suffocate while fully conscious and unable to move.
Placing the gun near the place where your nasal cavity meets your mouth area would lead to a shot straight through the postcentral gyrus and most of the parietal lobe, which together form your sensory input area. You will be blind, deaf, incapable to interpret any sensory input and for all intents and purposes unconscious, because none of the signals your brain receives will be processed anymore. If you have bad luck your ears may not pop and you could still understand speech for a minute or two, but then it's hasta la vista, because SURPRIZE SURPRIZE: this area of your brain is also where the main blood vessels enter, and you will bleed out far quicker.
Using a mirror to aim your shot properly would help.
The standard method of putting the gun against your temple will also miss most of your brain entirely, it simply grazes the frontal lobe and ruptures the optical nerve, leaving your blind and incapable of thought while still feeling the pain. Placing the shot a little to the rear (through your ear) will mean that you hit your brain dead center, causing the sensory center too shut down, and destroy some of your brain stem.
If there is something propping you in an upright position (like a wall or a seat), that means that you will bleed out slower, because your heart would need to pump against gravity.
You want to know how you can circumvent all of these problems at once?
Cut oxygen supply to the entire brain at once. This can be done by either hanging yourself (no blood reaching the brain), cutting your wrist (no blood to transport the oxygen anymore), or by using an exit bag (no oxygen inside the blood anymore).
There is a reason people used knives and ropes for executions and suicide long after firearms were invented.