Range spells and range combat feats.

Can you add ranged combat feats to ranged spells that require a attack roll to hit.

Oftentimes yes, but it depends on the feat and the spell. Deadly Aim often doesn't work since most ranged spells target touch AC, and some other feats apply specifically to weapons. If it is a feat that references a ranged weapon, then ray spells will usually work with it but most others won't.

As Ssalarn said the answer is usually yes, but it may depend a little on the situation so it is hard to give a blanket yes.

What did you have in mind?

I was just trying to come up with a magic gun type concept without going the spell slinger way. I didn't want to try this then found out I can't lol.