I finally, and I repeat finally got this achievement after 6 hour of cussing, screaming, and throwing my controller. I had to do my best NOT to take out my frustration on my wife, because she felt so bad watching me do this.
Ok here was my strategy in accordance to the ones already said.
1) I used the xbox controller the "MW3 Edition if that counts for anything.
2) I turned my sensitivity to 1.
3) Turn OFF vibration it only throws you off.
4) Screen walkthrough:
Screen 1 steps:
2 Wolfs right hand side ----KILL
3 Wolfs running left -------IGNORE
3 Wolfs they tend to Run from right and left ----KILL
2 Caribou -----KILL
3 Wolfs chasing Caribou -----IGNORE
Screen 2 steps:
1 Wolf in center, Kill that bastard wolf quickly ---KILL
3 Caribou being chased ---KILL
*When you kill all 5 Caribou you get Bear Scene*
1 Bear ----IGNORE
3-4 Wolfs one of them might have health ---KILL
*Must get Unlimited Ammo Power-up*
Screen 3 "The Sh*t storm":
Wolfs are unpredictable in this scene some other people have good strategies here all I can say is.
*Don't activate Unlimited power-up until second half or until caribou with health run by*
Screen 4 steps:
2 Wolfs running right -----KILL
2 Wolfs running left -----KILL
2-3 Wolfs running around 1-2 w/health ----KILL
Screen 5 steps "Mop up":
3 wolfs running from left----KILL
1 wolf bottom right -----KILL
*That wolf has unlimited power-up*
Here's: that part that will benefit you in the next rounds or at least what I did to make my life easier.
Gun down all the wolfs but make sure you gun down the wolf with the SLOW MO Last to save for next round of waves.
Okay for the next runs use this strategy*******
Do everything from the steps before but when you hit screen 2 do one of two things:
1) try and kill that wolf before caribou run by if you fail mop them up with the slow-mo.
2) If you did get the lucky shot on the wolf and the caribou without using your slow-mo. Save it for the 3 wolfs near the end of screen 2 when they run out. USE the SLOW MO. Mop up the 3 wolfs, and kill that unlimited ammo wolf.
When you reach the 5:00 Minute mark or the last run through. Put the controller down for 10 minutes. TRUST ME. This will give you time to stop shaking, and put that heartbeat of yours a rest. Take this 10 minutes to relax and when you come back you will up to snuff again to mow down some more wolfs.
Me Personally: I had to take 2 breaks I paused in between scene 4-5 to take a second 10 min break because my hands and my heart was racing knowing I was so close to finally beating it. I had to calm myself back down and take a quick shot of vodka.
With some luck and some practice it is possible. Just near impossible.
Thanks to Shoe478