Must Have Sentry ( Mainly The Sentry Gun ) Where You Spawn You Will Run RIght Through The Little Tunnel And You Will See The 'Equipment Armory' Blow Up The Vehicles There And Kill Until Wave 10. DO NOT BUY WEAPONS. Only Pick Up Weapons They Drop And Replace Old Ones Until Wave 20+. But Well Get To That Later. On Wave 10 You & You're Partner Will Need To Buy A Sentry Gun ( Or Only One Of You Works Fine ) And Place It On-Top Of The Transport Truck Infront Of The 'Equipment Armory'. Anytime That Sentry Gets Taken Out Buy Another And Place It Upon That Vehicle. They Should Last About 5 Waves Each. Next We'll Talk About Were To Camp. In Survival Theres No 'Perfect Spot' To Camp, So Beside The Truck Where You Placed The Sentry Gun Sit Behind That And Just Nail the Bitches As They Run To You're Trap. On Juggernaut Waved You Will Need Flash-Bangs. When He Slides Down The Rope And Begins To Shoot Throw Only ONE Flash-Bang Untill He Starts To Fire Again, Then Throw Another (Should Only Take Two Flashes Per Jugg.) This Spot Will Only Last Until About Wave 20. Then You Will Pick Up You're Sentry And Move Back To The Spawn, You Will See A Building With Stairs Leadng up Only Two Ways, Place You're Sentry On The Stairs Where It Can Still Be Effective. By Now You Should Purchase Weapons And Rapidly Refill Flash-Bangs And Fragmentation Grenades. I Found The ACR 6.8 W/ Red Dot Very Effective On These Higher Rounds. The Grenade Launchers In Survival Are Worthless Do Not Purchase These Unless You Want Too See For Yourself. Dont Be Scared To Toss A Few Flashes And Frags. Over The Rails. If You Or You're Partner Ever Get Down, ALWAYS Re-Purchase Self-Revive From The 'Equipment Armory'. Many Of The Airstrikes Come In Handy Too, Such As The Airstrike. If Many Enemies Gather Up , Toss A 'Airstrike Marker' And Watch Them Fly. Rounds 40+ You Should Be Buying 'Delta Squad' & 'Riot Shield Squad' To Assist In These High Rounds. From There Its Up To You. If You Have Any Other Strategies Please Post Them I WOuld Love To Test Them, Hope I Helped Guys!