Does a nail gun have to press against something in order to fire ?

Modern ones need to be touched on something to fire. 

Nail guns come with different types of triggers and safety features. ... The user must press the contact safety tip into the material that will receive the nail and then depress the trigger. Both must be released and pressed again, in the right order, for the tool to fire the next nail.

Yes.  A Nail Gun only works when it's pressed against something and the operator pulls the trigger.

Usually YES.  It could otherwise be used like a weapon, and there are plenty of bloody idiots  about who would attempt to do so.   It could also be dangerous to the professional user.

MOST nail guns have a  built in safety device to prevent firing into the air. ANY such device can be bypassed.

Yes it must be pressed against something before it will drive the nail.

It is a required safety feature for many years.

However, it is mechanical and subject to malfunction.

And some people deliberately bypass the safety feature.

every one I've seen has to be pressed up against the wood target to disengage the automatic safety

yes , its the safety device built in it so you dont nail yourself to something .

yes they have a built in safety to prevent accidental discharge, these can be circumvented but its not recommended 

All you need to know....

https://www.youtube.com/watch?v=F1tEYnl5sqA&ab_cha...