[usmcveteran]

Do you have a BFA (blank firing apparatus) for your AR? basically goes over end of barrel and you screw in piece that blocks muzzle so there is enough pressure to cycle the weapon.
Are blanks legal in NYS?
finally I would say you shoould be fine because I assume you have permission of the owner of the building and secondly the intent IMO of that rule is because of projectiles moving through air and safety concerns. BUT you are still firing a weapon (unless there is definition in the law that says a projectile is fired) so they may be able to get you anyways.

 

[usmcveteran]

It would be in Environmental Conservation law. Thats where the law your asking about is found.
Laws of New York
they might have a definition there but I am not sure. Also even though I know you know back sure your not pointing it at anyone or anything combustible when firing it.

If you or no one finds anything in there I will give it a quick look tomorrow and see if I can find anything relevant.

 

[usmcveteran]

I did find a few things in the law.

Here is the most important part I found.
Laws of New York

§ 270.00 Unlawfully dealing with fireworks and dangerous fireworks. 1. Definition of "fireworks" and "dangerous fireworks". The term "fireworks," as used in this section, is defined and declared to be and to include any blank cartridge, blank cartridge pistol, or toy cannon in which explosives are used,................
3. The provisions of this section shall not apply to articles of the kind and nature herein mentioned.........
the sale or use of blank cartridges for a show or theatre, or for signal purposes in athletic sports, or for dog trials or dog training,

I also found the following Laws of New York

§ 265.05 Unlawful possession of weapons by persons under sixteen. It shall be unlawful for any person under the age of sixteen to possess any air-gun, spring-gun or other instrument or weapon in which the propelling force is a spring or air, or any gun or any instrument or weapon in or upon which any loaded or blank cartridges may be used, or any loaded or blank cartridges or ammunition therefor, or any dangerous knife; provided that the possession of rifle or shotgun or ammunition therefor by the holder of a hunting license or permit issued pursuant to article eleven of the environmental conservation law and used in accordance with said law shall not be governed by this section. A person who violates the provisions of this section shall be adjudged a juvenile delinquent.
This link talks about permits for display of fireworks. Laws of New York

It appears to me from my limited research you basically need a permit in order to legally use blanks. I hope the above helps more then it confuses.

 

[usmcveteran]

Not a problem.

 

[usmcveteran]

You may still need to shoot it to signal a race (remember NYS wants all your money lol).