Originally Posted by Takatori
Are you sure you tried Sniper Attack? I was on Sniper Attack on Corvette earlier and the Elites appear on the 5th wave. As far as I know the waves are always the same (I've done Sniper Attack on Corvette quite a few times). Managed to rack up 8 Elite kills and then I finished the Round not long after. It's pretty easy really when you have Sniper Rifle and infinite Ammo.
The waves do change. There is one load out where the final wave is all brutes, then one where there are like 10 Elite Jumpers. Then another with heavy elites that all have plasma cannons heavy weapons.
Regarding today's 50 assists.
DRIVE a warthog!!! You can get assist after asssit on one, especially if you have a good gunner. I do BTB and just keep the pedal to the medal. I never, EVER stop the truck for any reason, take wide, fast turns and let the gunner go nuts.