There are many rules to consider regarding Olympic shotguns:
-Shotguns with magazines must have the magazine blocked so it won't hold more than one round.
-Release triggers are allowed in USA Shooting (USAS) sanctioned competitions, but USAS rules also note that a competitor using a release trigger can't compete in any finals rounds, and can't make the National Team, National Development Team or any USA Shooting Team.
-No slings or straps are allowed.
-As long as your gun is functioning, you can't swap parts or guns during a given round.
-Compensators and similar devices are allowed for Skeet but prohibited in trap events.
-Barrels may be ported, provided the jury has inspected and approved them, and they meet ISSF requirements.
-Here's what they say about optical sights: "All devices fitted to the gun, which have magnifying, light emitting forward lead displacement properties or give visual enhancement of the target, are prohibited."
-All guns must be visibly open and empty when carried.
-At the station, the gun can't be loaded until the command "start" has been given.
-No shooter may leave (or even turn from) the station until his gun is empty and this has been confirmed by an official.
-Closed guns may not be handled when anyone is in front of the firing line.
-When not in use, guns "must be placed in a gun stand, locked gun case, armory or other secure place."
-Aiming exercises are allowed only in designated areas, with the referee's permission.
-Don't aim or shoot at other shooters' targets, live birds, or other animals.