It certainly seems to be a live fire prop that was supplied by Bapty as far as I can tell. The prop uses both the Hero's scope and scope mount, although configured differently. The base C96 also seems to be bull barreled, which is why it was thought that the same base gun was the Hero prop's (just having been broken down and put together differently).
Nowadays I think the idea that Bapty had several Mausers that had been modified to have rifle barrels is more of a commonly accepted theory, so it's impossible to say with certainty that the Bunker blaster uses the same base C96 as the Hero... Although there is no evidence of the mystery disc, so make up your own mind.
But the unique mount and scope place it 100% as from Bapty.
Again, just to borrow a picture from Markus:
It seems to have been something like this, with an unidentified flash hider(?) on the end.