Viewing the evidence in the light most favorable to defendant, there is nothing to support a finding that defendant had a reasonable belief that the copper-colored flattopped bullets that he loaded into the revolver before pointing and firing it at the victim were in fact blanks, and could cause no harm. Defendant's information that the bullets were "blanks" was third hand, and he did not test them or otherwise verify their nature. Such disregard of the possibility that the bullets were live was a gross deviation from the standard of conduct that a reasonable person would have observed in the situation, and therefore "reckless[]" within the meaning of Penal Law § 15.05 (3) ( see, Matter of Mario Y., 75 AD2d 954). Defendant's claimed mistaken belief that the bullets were harmless was not based on a known fact regarding their nature, and therefore was not a "factual mistake" within the meaning of Penal Law § 15.20 (1) (a) as would excuse his conduct ( see, supra). Accordingly, any error in the trial court's charge on the mistake of fact defense was harmless.