By Gabriella Borter (Reuters) – An on-set shooting death has reignited concern about the use of prop guns like the weapon actor Alec Baldwin discharged in the killing of cinematographer Halyna Hutchins while filming a movie in New Mexico. Some prop guns are non-firing facsimile weapons, but many are real guns, loaded with blank rounds instead of bullets. Prop guns have long been used on sets for the realistic visual effect of the flash and recoil after an actor pulls the trigger. Guns with blank cartridges, which lack a bullet but use gunpowder, can be fatal at close range. Productions using p…