I did it!

I finally got 500 headshots with one gun in MW3, which completes all the challenges for the PP90M1.

Or so I thought...

Some of you have been wondering why I haven't followed you into Prestige mode, sitting at Basic 80 while you all go off earning street cred with your pretty colourful symbols and all. Well I've opted instead to finish all the available challenges for one weapon, which is a time-consuming endeavour. I had already done all the kills and attachment challenges (some of which sucked bigtime), but found myself short on headshots. Each time I thought I had all the headshots needed to complete the challenge, another entire level of them would appear. First 250, then 350, and finally 500 headshots. No mean feat with an SMG, I might add. So I was very excited to finally finish all 8 levels of that particular challenge, which completed the set.

Yet the main SMG challenges summary screen seems to indicate that I'm NOT done, saying I've only got 11 of 13 challenges complete:

Except when I look at the breakdown challenges for the PP90, all possible bars are full:

But there are only 11 challenges on the list!!!

Fearing that this may be yet another Modern Warfare 3 bug - or worse: a hidden challenge! - I decided to do some research.

Let's just say that Google was less than helpful, and I've got a black belt in Internet. So I took a different approach, and turned my attention to the unlockables. The new PP90 emblem was nice, but I found it odd that there was no corresponding "title" graphic. The sequence seems to be metal, metal with blood, wings, and then skulls, according to what I have now.

But I'm pretty sure I've seen another title graphic out there similar to the skulls one. So let's look at the other weapon titles I've earned:

Dammit! Sure enough, there's room for one more graphic between the other guns on the list. This is going to require further investigation.

A few websites showed the same random assortment of titles and emblems (probably stolen from the same source), but in no particular order. Then I found mw3nation.com, which not only shows ALL the graphics, but also how to get them!

And that's when I spotted it... the spine-tingling beauty I'd randomly seen online one night:

Very nice. Now all I need to do is get... 500 MORE HEADSHOTS?!!!

Now you're probably wondering "why the hell doesn't it show that challenge in the game itself?" To answer that, you'd have to be one of the morons at Infinity Ward. But for a chuckle, let's go see what it says on Call of Duty Elite. I am paying for it, after all.

Sure enough, all challenges for the PP90 are at 100%:

But wait, a minute, there seems to be 12 challenges listed here!

So now there's a challenge called "PP90M1 Master" and one called "PP90M1 Mastery"? I'm starting to think Revek works there. But wait- there's a locked tab under the challenge for headshots! What could it be?!

Sure enough, there's the challenge that's missing, as hinted by mw3nation.com. So all I need to do is get 500 more headshots and I'll have everything possible for the PP90M1, right?

Well, let's do the math. The game thinks there are 13 challenges. We found a new one on CoD Elite: "PP90M1 Mastery", but I already have it, according to that site. And doing all 1,000 headshots won't necessarily give me another completed challenge, as I already went from 10/13 to 11/13 with the "PP90M1 Expert VIII" (headshots) challenge. Even if I did, that only takes me to 12 out of 13 challenges, leaving us with yet another mystery. And that's assuming that it's headshots I need, as the site inexplicably only lists everything as "kills".

Fuck this, I'm prestigeing.