Barrett .50 Cal wins. More Ammo, Higher clip, less idle sway. The Barrett and Intervention are -identical- in terms of damage, multipliers and "Hit Markers" If you get too many hit markers with the Barrett, you suck with it.
Don't get me wrong, I love the intervention and it's all I use when I quickscope competitively (Usually get around a 9-kill streak or so before dying, so I play 5-7-9 -That's without using my PM/Harrier, @ 9-kill streak. I've gotten a nuke from quickscoping before.

) But anyway, they're identical, and I prefer the Barrett .50 Cal when I'm playing aggressively. If you can resist the urge to spray the second you miss or get a hit marker, it resets on its sights faster than the intervention's bolt, so... Also, if you can manage to learn how to do this, you may be better off with the Barrett as well

[ame=
https://www.youtube.com/watch?v=sMEVEBtMzLM]YouTube - MW2 - Recoil Abuse[/ame]