That would be a hero prop
replica, of course -- as close a copy of the real McCoy as circumstances allow.
But to look at the differences between the actual hero vs. stunt
props, that still works as a starting point:
- A hero Pulse Rifle prop would have been built from real, firing M1A1 and M870's, with all the electronic and moving gizmos. These would have been used in the close-ups, e.g. when Hicks instructs Ripley in the use of the weapon or when Ripley loads up in the elevator, and anywhere the gun needs to be seen to fire.
- Stunt props would basically have been cast in a single piece using a hero as master, possibly with some added detail when needed, and in the case of Aliens, been used at any point when people just carry the weapon around, run about with it, etc. In this case, they would also have been much lighter.
But the terminology
is tricky. There are of course what I think most people mean by "hero props": the fully operational beauty props that look as good as they can, has all the working bells and whistles, and so on.
But then there are also "static heros": props that are finished to look just as great as the "working heros", but don't actually
do anything. These might for instance be used when an item needs to look seamless when not in use, and openings on the working hero are impossible to hide. Or when the "working hero/-s" is/are at another shooting location, and you don't actually need the functionality at the secondary location, but you still need closeups.
Some props of course have no working parts, so
any hero would by definition be a static hero.
Furthermore, there are also "working stunt" props -- stunt props that have
some operating detail, such as a light or some pivoting/rotating/telescoping part, but are otherwise completely inert, and are made out of simpler materials.
And finally, there are the "static stunt" props, the urethane castings, wooden, vacformed, etc props that are used in background shots, carried around
en masse by extras, action/fight sequences, dangling from a belt, etc.
Unfortunately, not even these definitions cover all the permutations out there -- far from it...
All in all, in the terms of our hobby, I don't think I've
ever encountered the term "hero prop" being used merely to denote "a prop used by the screenplay's protagonist".