Tip for folks using Airsoft shotgun props in their films: NO pump action shotgun has a BOX magazine (okay okay, there actually *are* pump action magazine fed shotguns - examples: this and this. But most shotguns seen in movies that people try to replicate with airsoft shotguns, like Remington, Winchester, and Mossberg, do not look like this.). The entire point of pump action is that you are pushing another shell down the tubular magazine under the barrel and into the chamber...so there is no need or point for the box mag. Leaving it in just designates it as Airsoft and pulls viewers out of the film. Just take the damn erroneous mag out of the gun and then you can go to town. Now this is common in your usual youtube shootout videos, but I've seen it in a couple of modestly budgeted B-movies as well.
It's no secret that even legitimate feature productions utilize airsoft guns (you don't want an army of untrained extras wielding real guns, after all) - in fact I spent a day on a TV set playing a cop, and my gun was airsoft. So were the M4s carried by the actors portraying soldiers. The only real gun was a demilitarized rifle carried by a guy playing a SWAT sniper. But if you're gonna use airsofts, you gotta distress them first. Repaint them. Dress them up. Whatever. Don't use them right out of the box! They look cheap and plastic-y, and if you leave the ridiculous accessory rails and cheap laser sights and mock "scopes" you're setting yourself up for disaster. And use guns that actually look like a real-world gun! A lot of airsoft manufacturers put out these horrid Frankenstein guns that have the body of an MP5, the magazine of a SIG-550, and the adjustable stock of an M4 carbine. They bristle with pointless attachments, scopes, chroming, forward pistol grips, and silencers. Ultimately it looks cluttered and ridiculous. Yes, modern guns like those in the M4 family are extremely customizable and you see this in movies. But think about all the action films you've seen. Save for a silencer or two on the pistols, most guns are *clean* with none or little accessories. It just looks slicker that way.