Sorry you've all missed dodics point.
"do you need to pay a license just for using REAL guns in your game"
Ie just like FIFA games have to PAY A LISCENCE to use the names of the football players, and Gran Turismo games have to PAY A LISCENCE to use Ford, Nissan etc cars, games that use a Beretta weapon would have to PAY A LISCENCE to Beretta. If the models in your games have the names or deisgns of REAL WORLD weapons which in the real world have a trademark or patent on them, it illegal to sell that game without contacting Beretta first. Ditto "Colt" weapons, and many others.