Since you are selecting a S Code, I would surmise that this is an acute injury to the hand. The S60 Code Set for "Superficial Injuries" is essentially limited to injuries involving the skin and immediate subcutaneous tissues, i.e. just below the skin. Anything deeper than this would be a "deep" wound and fall into the S61 Code Set for "Open Wound." Unfortunately, the writers/creators of ICD-10 did not use the term "Deep" along with "Open Wound" to differentiate it from "Superficial" as is used in S60. Also, and unfortunately, ICD-10 only seems to allow the terms "Laceration" (which is generally thought to be the result of slicing or tearing of the tissues), "Puncture" (which is generally thought to be the result of something "poking" through the skin into deeper tissues, such as a stab wound), and "Open Bite" (which is fairly self-explanatory). What ICD-10 doesn't consider is "Penetrating" wounds such as from guns (BB and/or otherwise). I think it should use both "Penetrating" and "Puncture" for wounds of these types, i.e. Puncture &/or Penetrating Wound .... A Gun Shot Wound is more of a Puncture Wound than a Laceration, so in your case, I would go with the S61.442A, particularly since the BB lies deep in the tissues between the metacarpals.
I hope this is more helpful than confusing, but since you and I didn't write the coding descriptors, we are left with trying to "decode" it.
Respectfully submitted, Alan Pechacek, M.D.
icd10orthocoder.com