If I had a gun I would literally instantly kill myself already without hesitation. A gun is almost guaranteed to kill you if you shoot ur brain from the inside of ur mouth and it's also instant and painless.
Eeeh... Since you're not doing a goodbye thread with a gun... And are torturing yourself with envy... I'll warn you of the worst case scenarios.
Guns can slip... Even the guy in fight club failed.
The most likely death us a shotgun, not a gun. And that's not even 100% sure.
Google failed suicide shotgun in images...
Try to find the gun suicide sid meme...
I'd take N or gas maybe... A grenade necklace.
I saw in a movie a guy digging a tunnel in a yard, blowing himself up, instant burial. Amazing.