Halo 3 odst question?

[balla]

the achievment be liek marty, the description is to go a full round without firing your waepon. when tehy say round does it meen round as in from start to finish of the game or round as in grunt and jackle round or cheiften round

 

[Robs McGee]

Each round I believe 3 drop ships come by. Just let your friends kill them and you just run and jump. It took me like 3 or 4 minutes.

Best of luck!