I posted about this before and have since refined and tried some new stuff. Sorry for any repetition.
I don't have melee weapons equipped with my ranger or gadgeteer and it's easy to run out of ammo, especially with my tripleshot Xbow, but if you put extra ammo in your alt. secondary slot, it will automatically reload for you even in the middle of a multi-shot.

Someone had earlier posted that all you had to do was put stuff in your inventory, but that didn't work. I had to use the extra turn to equip.

So as long as you don't mind using your gun or bows exclusively, that's a cool trick to be able to use those last few rounds without having to worry about wasting a turn to reload.

I said that in a post one time & i dont know what your doing wrong but it "does" work.

As long as you have the extra ammo in your characters personal inventory & not in the group inventory you can reload just by switching to you characters inventory screen & picking up a bundle from your personal inventory & putting into the slot you normally place ammo in.

I didn't ever try actually going to the inventory screen for it. If you equip the extra ammo in the alt spot, you don't have to do any screen switching or anything. It will even reload between the second and third shots on a tripleshot xbow. For the truly lazy (or forgetful..)