@Robhill Informed us that the achievement is now unlockable. A developer of the game told him it was fixed and it is confirmed by other gamers. Cheers!UPDATE 6:
There is still some issues with the achievements being bugged again. In an effort to be heard again they have issued a petition again (https://www.change.org/p/343-industries-phil-spencer-microso...
). Please sign it even if you have the achievement unlocked!UPDATE 5:
On October 9, 2014 Bonnie Ross sent a tweet notifying that they released a patch for the glitched achievements. Play now and get them!!! UPDATE 4:
In an effort to get this glitch resolved, Avenged FADE created a petition for this problem to be noticed. Please go here and support it (http://www.change.org/en-CA/petitions/343-industries-fix-the...
). There are a series of steps you could do to help even more. If you want the exact details go to the comments below. Thank you and happy gaming!UPDATE 3:
27/12/2013 In a forum thread there are players trying to look for a solution by informing to 343i. You can see the thread in the comments area below. Therefore all we know about this glitch is that they are still working on it.UPDATE 2:
As of 9/4/2013 this achievement is glitched for those who purchased the Champions Bundle DLC (thanks to SIP Crucio for the update). If you haven't bought the new DLC unlock them first and save a big headache! They are players trying to contact 343i for the issue.UPDATE
: The Light Rifle kills does not count for this achievement. (Thanks to a Good Gamertag for confirming it)
First of all this is a cumulative achievement. In other words it can be done by killing players in different matches except on swat (obviously).
Weapons that work for this:
-Light Rifle (for me this did not work...if I'm wrong comment and I'll change it)
-Binary Rifle (thanks CabbageWithPie)
I recommend equipping Support Upgrade: Ordnance Priority because it gives you a boost with the point to get an ordnance. Just play until you get an ordnance and choose any of the weapons mentioned above. If you want t increase your odds equip pulse grenades and a boltshot and get some lucky kills.
why negative votes? o.O I'm only helping!