how do the shotguns work?

the scattershot, shotgun and boltshot.

i’ve got this many kills with each
scattershot: 296
shotgun: 75
bolthot: 32

i’ve noticed that while the shotguns a bit easier to use, both the boltshot and shotgun basically kill the enemy immediatley if the reticle is in range and at center mass…

but like… the scattershot is a little bit weird. sometimes projectiles just blast all over the friggin place and off the walls while the targets squirming around and they sometimes survive…

the others don’t have that problem… or at least the shotgun. the boltshot i’m not sure of.
shotgun just seems to always do a certain amount of damage based on how far you are, even if they’re soaring thru the air or something. if they’re in the reticle they’re hit.

so… i’m pretty sure that the scattershot uses projectiles, but are the shotgun and boltshot charge hitscan? or what? i don’t know can someone explain the mechanics to me a bit?