Unless things changed in this edition you get DNI (direct neural interface) between your brains and wireless electronic devices (in general) simply by wearing trodes (or by installing a datajack, control rig, commlink, datajack or, new for this edition, a cyberjack).
Reloading a weapon seem to be a major action in SR6.
...or a major action where you get back a minor action if you use a wireless enabled firearm, but only if it uses a 'clip' and only if you also have DNI
...or a minor action if you reload a revolver with a speed loader
Reloading a smartgun seem to be a minor action in SR6
...or a minor action where you get a minor action back if you use a wireless enabled smartgun
Use Simple Device (manually changing firing mode without having DNI) is a Major action in SR6.
...or a major action where you get back a minor action if you use a wireless enabled Ruger redhawk
...or a minor action if you use any smartgun connected with a wire rather than wireless
...or a minor action where you get a minor action back if you use a wireless enabled smartgun
Change Device Mode (mentally changing firing mode via DNI) is a Minor action in SR6.
...or a minor action where you get back a minor action if you use any wireless enabled firearm.
...or a minor action where you get a minor action back if you use a wireless enabled smartgun