Re: Kingsman: The Secret Service, "Carnwennan 9mm" *finished!
They smooth over stuff on stunt castings all the time. Very common. Some times the back half of trigger guards are filled in. Some times they do it to protect the hero from rubber mold material getting into seams and actions and things, and some times it's so they can have a visual marker on set to distinquish the hero gun from the stunt guns. Heck, the pulse rifles on Aliens looked very different as the barrel shrouds were cast wrong. Still used 'em, and most viewers never noticed a thing while watching the movie.