Is there a difference between “metallic” hard rock and heavy metal?

Is there a small gray area, or are they essentially the same?

For example, I think the first LA Guns album is metallic hard rock.

That brings up another interesting question: what exactly defines heavy metal? What is the thing that makes both Nightwish and Mortification fit under this umbrella? The presence of low-tuned electric guitars? I ought to know as a metal head but couldn’t give a definitive answer to that question

seth wrote:That brings up another interesting question: what exactly defines heavy metal? What is the thing that makes both Nightwish and Mortification fit under this umbrella? The presence of low-tuned electric guitars? I ought to know as a metal head but couldn’t give a definitive answer to that question

Double bass drums is a common factor in most heavy metal. Also, metal tends to have a bit more aggression than hard rock.

It depends on how old the person is that you are asking.

For anyone under 30 it seems like the band needs to be Metallica or heavier to be labeled as Metal.

But the label "Heavy Metal" has been around even longer than all of those post Metallica bands.  Deep Purple, Black Sabbath, Montrose Uriah Heep, Nazarath, all these bands were considered Heavy Metal before Thrash and the heavier genre bands even existed.

Overall I'd say it's about how next it is... Until we get to hair metal, bc some of hard rock is harder than a lot of hair metal. But hair is definitely metal due to the structure. I can tell the difference, but I can't exactly put it into words. Nu Metal also can often be pretty close to being rock

These questions are hard to answer because the genres and subgenres are so intertwined now.   The demarcations used to be a lot easier to recognize years ago.

The AC/DC formula will always be in the hard rock realm. Even if a band plays the riffs with a lot more crunch and heavy gain. The structure is still hard rock. 

But if you play an Iommi riff or something from the less bluesy Priest style, it’s unavoidably metal.

Whitesnake also beefed up their style on the s/t 1987 album. It’s super influenced by Led Zeppelin, but the guitar sound is metallic on the uptempo songs.