Reddit mentions of Avengers & X-Men: Axis

For the overall story of the Marvel Universe, post-Civil War:

• Mighty Avengers, Vol. 1
  
• Feel free to pick up New Avengers, Vol. 1-2. They're pre-Civil War.
  
• New Avengers, Vol. 3
  
• New Avengers, Vol. 4
  
• Civil War: Captain America Read at least this, if not Brubaker's entire run.
  
  Then we lead into Secret Invasion:
  
  
• Thunderbolts by Ellis & Deodato
  
• Secret Invasion
  
• Mighty Avengers, Vol. 2
  
• New Avengers, Vol. 5
  
  Which leads into the new status quo--Dark Reign:
  
  
• New Avengers, Vol. 6
  
• Dark Avengers
  
• Siege
  
  The new era is called The Heroic Age. Most books did their own thing for a while, and then:
  
  
• Fear Itself
  
  The next major event spun out of events going on in the X-Men books from about 2005 forward. As a huge X-Nerd, I'm in no position to judge how readable it is for anyone not very familiar with the X-Books at the time. If you want, I can give you an essential reading list.
  
  
• Avengers vs X-Men
  
• Age of Ultron
  
  Similar to AvX, the next event comes out of the stuff going on in the Avengers books by Jonathan Hickman.
  
  
• Infinity
  
• Original Sin
  
  Again, an event comes out of another book--Remender's UNCANNY AVENGERS:
  
  
• Uncanny Avengers
  
• Axis
  
  
  

You can already get the Original Sin hardcover here: http://amzn.com/0785190694

The Death of Wolverine hardcover will be out next week: http://amzn.com/0785193510

Axis actually ended last month, and the hardcover will be out in March: http://amzn.com/0785190953

Hope that helps!

http://www.amazon.com/Avengers-X-Men-Axis-Rick-Remender/dp/0785190953/ref=sr_1_1?ie=UTF8&qid=1452698922&sr=8-1&keywords=marvel+axis
This?

Carnage USA was a follow up to the Zeb Wells Carnage series, from back in 2012. It has no ties to the story you're referencing.

THe comic you're thinking of is AXIS: Carnage, which was a tie in for the larger universe-wide event, AXIS.