The wording seems to indicate that it is applicable to heavy guns, rifles, and pistols.

Is this right?

P.S.
the title is suppose to be weapons not perks..

Please someone respond.

anything with an automatic receiver....it's really unclear if it includes heavy weapons or not though, I would wager that it doesn't include heavy weapons though because most of them can't be modded to have an automatic setting, the rifles and pistols tend to have the word Auto in their names when fitted with an automatic receiver and I would Imagine that's how the perk is distributed, buuut I could be wrong.

So because heavy guns are by default automatic they don't count as automatic?

Also, if you have both heavy gun and commando perk then heavy guns would have 200% more damage?

depends on the heavy gun we're talking about but assuming the obvious you're hoping the minigun count as an automatic weapon...balance issues aside the minigun functions a lot differently than normal automatic weapons, all the regular automatic weapons don't need to spool up to fire and they don't overheat either(not to metion them not all having electric motors and several barrels), so bethesda has probably programmed the minigun to be restricted to the heavy guns classification...but I dunno, maybe a modder will add it but if it is a thing already then that would be a bit overpowered.

So what exactly counts as a heavy weapon? Miniguns(+laser)/fatman/missile launcher...

Trying to figure out if the heavy weapon perk is even worth it. Finding enough ammo to feed my minigun is next to impossible.

Broadsider, Crylocator, Flamer, Fat Man, Missile Launcher, Gatling Laser, Minigun, And the best for ammo: the Junk Jet

Hmm, what I'd give for a perk to reduce the weight of those guns.

there's a reason why the heavy weapons perks are all in the strength tree, just for the additional carrying capacity, I often just hand one of my heavy weapons to one of my followers and pick it up when things are about to get real.

i did found a damaged junk jet but i don't know how to repair it. how to repair gear that is damaged?