I did a short film went in the WWII era which required the use of prop guns. My art department came brought in one of the guns they'd found and I was sure that it was a real, authentic, metal and wood rifle from even a foot away. The minute you touch it though, you realize it's completely rubber. They've got a lot of amazing, realistic, safe gun props out there to rent for film. The only downside is that that particular gun cost 300 bucks. Good stuff rarely comes cheap.