I think this is a ridiculous change by Apple, going completely against the idea of Unicode and consistent character displays across different devices. Author's suggestion is good, but I don't think that this was a necessary change by any means in the first place.
Unicode only says that it's a gun, and only recommends how it should look. IME's are free to make the emojis look however they want at their discretion. Note Samsung's saltines instead of chocolate chip cookies for "U+1F36A Cookie". Consistency is laudable, but we live in a world with multiple cultures, meanings, and contexts, so in the end consistency might actually be more harmful and reductionist.
The unicode code chart¹ actually says “PISTOL = handgun, revolver”, and the reference glyph (with a larger version on page 4) is pretty clearly a Beretta M9.²
① http://www.unicode.org/charts/PDF/U1F300.pdf#14
② http://www.beretta.com/en/m9/ and https://en.wikipedia.org/wiki/Beretta_M9
I can't figured out why you're getting downvoted. The reference seems valid.