The Globalizers solution is simple and to the point. Here is another more detailed strategy.
For this achievement, you want as many players as possible boosting this together. If you have more than 8 players though, communication will become an issue since XBox live parties are maxed out at 8.
Have one person designated as the chain collector and one person killing the enemy players. The person that is collecting chain will NOT get ANY kills. Each kill earns you 3 points towards your match points.
The person that is collecting chains will commit suicide 1 time throughout the match, preferably at the beginning of the match. The reason for this is because if you collect 10 chains and turn them in, you earn 125 points. Match ends at 250 points. 1 suicide will allow you to turn in 30 chains per match because after turning in 20, you will be at 247 points.
Once you get comfortable with this, you can have 2 persons designated as chain collectors, one using the commit suicide 1 time method and the other collecting 19 chains and neither player getting any kills.
If you get even more comfortable with this, you could add a 3 player getting as many chains as possible (up to 19) before time runs out.
The main goal is to get chains on the floor any way possible. These chains will not disappear during the match. Players that are not designated as collecting chains should die as quickly as possible, whether it be making their way the the designated killer, or committing suicide.
Here are some extra strategies that are map specific-
Parking garage- Jumping off the 3rd and 4th floors are a quick way of getting chains on the ground. It is easier for 1 person to go collect chains on the ground than it is for 6 or so players to meet in one area (that changes every 2 minutes)
Derby- No quicker way of getting chains on the floor other than meeting up in the designated drop off area.
The other map- Jumping off the building and or going to the middle of the map and using the rocket launcher to blow yourself up is the quickest way of getting chains on the floor.