Halo: Reach

Since the playlist update, this can only be obtained in Rumble Pit playing TU Headhunter on an Anniversary Map. The following Anniversary maps are available in Rumble Pit:

Battle Canyon / Beaver Creek
High Noon / Hang 'Em High
Penance / Damnation
Solitary / Prisoner

Please note that Headlong is not available in Rumble Pit.

This achievement can be very difficult to obtain without boosting as you are marked by a number with how many skulls you have over your head up to 9, then when you have 10 skulls you have a circular symbol over your head (this is important to note). Also note that even though it says the score limit is 25, if a player scores 10 skulls at once they automatically win.

Boosting Method:

Contrary to belief, it is possible for multiple people to get this achievement in a game, but you have to follow specific steps to get it to work. When I boosted this we had 4 guys going for the achievement so what we did was have everyone congregate in a predetermined area that was not a hill spawn and begin killing like mad, once a player got 10 skulls he goes and sits in a corner away from the fray. Continue these steps until everyone who is going for the achievement has 10 skulls (I would not recommend more than 4 at a time). Once everyone has their skulls, everyone go to the nearest hill spawn (there are two at a time in some cases) and stand near it BUT DO NOT ENTER IT!!! Wait for the hill to move away from the spawn you are near, then everyone go and stand at the hill area so that when it shifts back, you will be inside it. Now everyone huddles together and waits, it may take a minute or two, but once the hill shifts back around, you will all score your skulls simultaneously, making the game a draw and netting everyone inside the hill the achievement.

Comment or P.M. me if you have any questions.

Bounty Hunter Achievement (75 Gamerscore):
Anniversary: Capture 10 skulls at once in a matchmade Headhunter game.

Notes:

- I suggest people looking for more information to look in the comments section of this solution, so you know who deserves credit for most of this solution, and possibly for a better explanation for some parts. Also, please let me know how to improve this solution.
Thank you.

1: You need to play on an Anniversary map, so you need the Anniversary maps Downloadable Content (DLC).
2: The 7 Anniversary maps (The Anniversary maps are maps from Halo: Combat Evolved (Anniversary), and Halo 2) are:
Battle Canyon (also known as Beaver Creek),
Breakneck (also known as Headlong),
High Noon (also known as Hang 'Em High),
Penance (also known as Damnation),
Ridgeline (also known as Timberland),
Solitary (also known as Prisoner),
Installation 04 (Firefight only).
3: There should be a number above every player's head telling you how many skulls they have (A symbol should appear if they have 10).
4: The capture point should move, throughout the match. When a capture point is about to move it should start flashing.
5: Skulls should stay throughout the match, if they are not picked up.
6: The match should end after someone captures 10 skulls at once, even if they don't have the required 25.
7: There is a legendary medal (Skullamanjaro) for capturing 10 skulls at once.
8: Players that have not picked up any skulls should drop 1 when killed.
9: To increase your chances of getting an Anniversary map you can delete the Defiant, and Noble DLC map packs (if you have them).
10: Quitting too many online matches can get you manned from playing online in this game, for a while.

Method 1

Probably the most challenging method is to do this without Boosting, or using a glitch.

1: You could use extra controllers to increase your chances of success, if you want.
2: Search for a match in the Anniversary Free For All (FFA) playlist.
3: Vote for a Headhunter game, on any of the Anniversary maps.
4: I suggest killing opponents with the most skulls (5+). Also go around the map collecting as many skulls as you can.
5: Play until you get 10 skulls. Be careful not to capture your skulls before you get 10.
6: Quickly get to the capture point. It is best to stay close to where the capture points are, so you are closer when you get the 10 skulls. It is also best to stay close to them because people will be going to them to capture their skulls, so you could take their skulls but you are at a higher risk of being killed yourself.
7: The match should end giving you the Skullamanjaro legendary medal, and the Bounty Hunter Achievement.

Method 2: Achievement Trading/ Boosting

You can boost to make this Achievement easier. I suggest looking at Panzer x360a's solution for a great method on how to boost this Achievement.

Method 3

- According to GoreGoyle: "You need to search under Rumble Pit with multiple controllers. Switch the profile on one of the dummy controllers as soon as the voting option shows in the lobby. Headhunter will pop up at least once per 2 rounds of voting."

- I would like to thank NURSEwithWOUND for a great idea, and Opto Jock for confirming: This solution does work for other online Achievements, except team based Achievements because it places your controllers on your own team.

- jack Burton 78 said: "My suggestion is to leave you main controller in place somewhere the score points don't move to and run your guest controller over to it. This makes finding yourself easier as well since it throws a beacon over the skull collectors head."

There is a glitch you can do to get this Achievement by yourself. It requires multiple controllers.

1: Sign in multiple controllers.
2: Search for a match in the Anniversary Free For All (FFA) playlist.
3: After you find a match sign out with one of your other controllers. This should disconnect you from the online game but still let you play.
4: Vote for a Headhunter game, on any of the Anniversary maps.
5: Play the match killing your other controller's player's until you have 10 skulls. be careful not to capture your skulls before you get 10.
6: Capture the 10 skulls.
7: The match should end giving you the Skullamanjaro legendary medal, and the Bounty Hunter Achievement.

I should not take any credit for this video, all credit should go to the Achievement Hunter Community (Rooster Teeth Community).

Panzer x360a's Boosting Method is excellent (i.e. everyone works towards getting 10 skulls each, and then once everyone has it, moves to a NON-active capture point and waits until it becomes active), but getting Headhunter on an Anniversary map is NOT only available in Rumble Pit. You can also get it in the Team Objective playlist.

In fact, my group was unable to get Headhunter on an Anniversary map at all in Rumble Pit after trying for almost an hour. While in Team Objective, however, it only took us a match or two for Headhunter on an Anniversary map to pop up.

So remember:
- Use the boosting method mentioned here and in Panzer x360a's solution to efficiently get everyone in your party this achievement in one match.

- Search for Headhunter on an Anniversary map in RUMBLE PIT or TEAM OBJECTIVE (I'd suggest trying Team Objective first)

- Anniversary Maps are:
Battle Canyon / Beaver Creek
High Noon / Hang 'Em High
Penance / Damnation
Solitary / Prisoner

Hope that helps!