I was just speaking with someone last week about firearm discharge laws. I believe that at the State level, it is illegal to discharge a firearm within 500ft of a residence. Nothing else in state law about this.
The person I spoke with insisted that both Nassau and Suffolk have their own restrictions prohibiting discharge. I was determined to find out the truth. In searching, I came across a great resource for local law/codes:
http://www.generalcode.com/Webcode2.html
From here, I found some interesting information that pertains to both gunpowder firearms as well as the BB/pellet guns in this thread.
Neither Nassau of Suffolk have any laws regarding discharge of a firearm. However, most TOWNS do.
As it relates to this discussion, it appears that in the Town of Babylon for example, discharge of a gun - gunpowder, BB or otherwise - outside of a licensed range is illegal.
Section 121.1
FIREARM
A weapon which acts by the force of gunpowder or from which a shot is discharged by the force of an explosion, as well as an air rifle, air gun or BB gun.
PROHIBITED ZONE
Constitutes all the unincorporated water and land areas of the Town of Babylon lying north of the east-west channel of Great South Bay.[Amended 11-15-1983]
121.2 exceptions
B.
Rifle ranges or similar installations constructed in accordance with the provisions of the Code of the Town of Babylon and fully contained within a structure or structures are excepted from the prohibitions contained in this chapter.
121.3
Discharge of firearms restricted.
No person shall discharge any firearm within the prohibited zone of the Town of Babylon.
Unless I am reading this wrong, the only place you can shoot a BB gun in the ToB is a rifle range built to code. Of course, other towns have their own laws/codes so it may be legal where you live. From the few I looked up, Babylon seems the most restrictive (doesn't get any worse than "absolutely not"). Other towns seem to have restrictions based primarily on noise. For example, Islip states "The use or firing of explosives, firearms or similar devices so as to create a noise disturbance." So firing a gun isn't the problem, but if it creates a "noise disturbance" you are in violation. BB/pellet guns would seem to be fine with this rule.
Then you get to town level rules. Look at Oyster Bay Cove where it is prohibited to: "Carry, point, aim, discharge or otherwise use any firearm or weapon in the open air within the corporate limits of the Village;". They define "weapon" as "A bow and arrow, crossbow, blow gun, sling shot, CO2 gun, air gun, BB gun, or any other device which emits a projectile with a force other than an explosion." So there, it is illegal to simply carry a BB gun. They probably lock you up and throw away the key for shooting one!
I cannot believe that people actually have the time to sit around and dream up these ridiculous restrictions.
added: PapaBear.. the Oyster Bay Cove rule is one of the few references I can find to sling shots. Can you point me to a source for your statement regarding them? Not trying to be argumentative, I am just looking for resources so I have a reference on the topic. From what I have read in the codes, it would seem sling shots are legal to own/operate in most areas.