Very simple, in ships capable of having a crew or passengers (like the Moth and Atlas), allow reloading from the cargo hold.

It would be beneficial to traders (as they would be able to have a snowballs chance in Hell against a pirate).
It would be beneficial to pirates (as they could use ships with larger cargo holds as pirate vessels).

This would be something on the gunner's menu to perform?

Would you be okay with some kind of cooldown period associated with this?

Without that, given player automation and optimization, it basically turns into much larger weapon capacity.

A traders hold would be full of cargo so it would only benifit pirates as far as I can see

Having said that +1

I think a 10 second cooldown for reloading is appropriate.

What about also having the cooldown process deactivate all/any other weapons, including energy and turrets? A moment of vulnerability for the luxury of reloading in space...

Personally, I think it should depend on the munition size, so for something that only shoots 2 missiles it'd be ~10 seconds, but for the larger capacities it could go up to 30 seconds to a minute. I'd add though that after 'using' one from your inventory, you shouldn't have an empty spot in your cargo, so you have to actually go to a station to sell the empty guns. Something to level out how OP it would still be against a fully loaded ship.

I'm curious as to how this would work. Would you load up crates of ammunition or just pile extra loaded launchers in the hold? I'd prefer the second one as it also induces a weight penalty.

As for traders not using it, I could see them being willing to sacrifice 2 or 4 cu of space in a standard behemoth to have mines enough to deter a pirate for more then one or two sectors.

A cool down or 'reloading' time definitely seems appropriate.

Back when I did a lot of trading, I would have gladly given up some cargo space to be able to reload my mine launchers.

I feel like 30 seconds to a minute is a bit much (as it would effectively be a death sentence) but it would make sense that what ever you are reloading would take some time to reload.

+1

Very simple, in ships capable of having a crew or passengers

This would include player controlled capital ships as well right? If so, +1.

in ships capable of having a crew or passengers (like the Moth and Atlas)

I missed this (learn to read bro)...

I'm fully against this asinine, arbitrary, reality-clinging idea that someone has to manually reload the ammo in a futuristic ship, when we can otherwise dock and undock from a station or ship and reload instantly.

If we can click a button or have it happen automatically (with a delay), fine. But if any aspect of this requires another person (gunner) or some clumsy journey into your cargo hold accessing some lame layer buried in the HUD to reload...then hell no.