hey writers we have to talk.
if you've read any romance or fanfic in the past twenty years (i know you have), you know that there are a certain number of scents associated with hot dudes. you can probably recite the list of Things Men in Fic smell like in your sleep: leather, black pepper, pine, sandalwood, "something uniquely him", clean sweat, and if the character has ever fucking been within 50 yards of a firearm, something called "cordite".
NO ONE SMELLS LIKE CORDITE.
cordite was a highly specific type of smokeless gunpowder developed in the 1890s by england specifically and used mostly in wwi.
if your good-smelling guy is not (a) english (b) using a very specific type of british rifle (c) dying in a trench in flanders, he does not smell like cordite. technically even if he does meet all those conditions he still doesn't smell like cordite because he smells like trenchfoot.
the point is, cordite is so far from universal that no one but the most hardcore gun nerds give a single shit about it. making your Sexy Hero smell like cordite is like naming a cassette-only bootleg live recording from the 1970s as your favorite grateful dead album. everyone at the party hates you immediately and knows you're doing it for clout. also, it's just factually... wrong. please stop. i know everyone else is doing it, but you can do the right thing here, i believe in you.
so what do people who are using guns smell like?
well if your story is set before the late 1880s, the smell of a fired gun is black powder, which, unfortunately, smells like seventeen flatulent cows have been shoved in a tire factory. trust me, you do not want your Hot Dude to smell like black powder. it's b a d.
if your story is set after the late 1880s, guns are using some variety of modern 'smokeless' powder - which speaking broadly doesn't really have a ton of scent when used. it does have some, but it's sort of non-descript: the best way i can describe it is the sweet, ozone, hot-plate smell of popping your car hood with a warm engine.
people who use guns a lot don't smell like fired guns all the time anyway, so while those scents might work in a fight scene, they're not realistic all the time. but there are some things that your Sexy Shootist will smell like basically 24/7 and that's metal and gun oil. metal you can go and sniff (i recommend non-stainless steel), but if you want a reference, most gun oils have a sharp, organic smell that's not dissimilar to canola oil but muskier and with a tang overtop. it's not unlikely leather is in the mix as well due to routine handling of leather equipment and gear. modern gear also tends to have a certain smell although it varies by production country and storage conditions - lots of opportunities there.
in conclusion: gunslingers and hired killers and military folks can be sexy and smell great on page, but i am begging you not to say "cordite" when you mean "gunpowder" ever again. we can do this. we are writers and therefore pedants. i believe in us!