The issue, as far as I can tell, is down to the CoD servers, I get them too and only noticed them after building my new PC, which might mean 1 of 2 things, 1 my new hardware is the issue or 2 the issues didn't really start until Season 4.
I took my old PC offline just as Season 4 started, my new PC took a couple of days to build as I was waiting on parts but this had bad micro-stuttering when I finally got round to playing CoD, so I sent back my GPU and upgraded, while I was waiting for my GPU we moved our router to a clearer spot in the house and then after it came there no micro-stutters.
Again, we can conclude either the new GPU or the newly located router fixed the issue, but I am not inclined to believe both are wrong and in fact, it was either a temporary fix, a reduction in player numbers or just coincidence that the situation improved shortly after changes at my end.
When I see a few people all complaining about the same issue with micro-stuttering though, I can't see a common denominator, unless you're all using some of all of the same hardware as I am using and if none of you are then it simply has to be a factor that's external to our hardware.
If it is an external issue then all we can do is send messages to IW/Activision support to say WTF getting bead micro-stuttering, server issues bro, fix up please! Or words to that effect.