Airsoft Restrictions Law, Rules, and Speed Limits
USA
No legal limit on pellet velocity. Generally limits vary from 350 to 400 ft/s (107 to 122 m/s) urban and from 450 to 500 ft/s (137 to 152 m/s) in woodland.
Not legal in New York City Metro (5 Boroughs), portions of Michigan, San Francisco, and Washington DC.
Must comply with two criteria: muzzle permanently colored in blaze orange and all non-licensed trademarks removed for copyright reasons on the Airsoft guns (this law recently expired on the federal level; however certain states still have and enforce it).
others
Import restrictions
All Airsoft guns shipped to the USA must remove copyrighted words when they go through customs.
Barrel markings
Due to extreme similarity between these replicas and real firearms, combined with lobbying efforts from U.S. BB gun manufacturers, some U.S. states and local regulations may prohibit the ownership or use of Airsoft guns. Federal importation laws require all Airsoft gun barrels to be painted with a minimum 6mm wide blaze orange stripe, as must all "toy guns". This measure is intended to avoid confusion with actual firearms.
here is a quote from some other airsofters too.
"I live in Tucson Arizona, we were out waiting for some guys to show up for a game of airsoft. Two officers approched us and asked us to leave our "Guns" against the wall as they were and come down to them to "Talk" the one officer whent up to check out the airsoft guns, while the other was checking us for any "Hidden firearms" after that was through we were told that it is a "FELONY" to discharge an airsoft gun "within city limits"