I wouldn't call this a "major" issue at all. Sure it'd be nice to have it LOOK like real life, but that's only aesthetics. Does it impact the functionality of the simulator? Not so much.
May 9 2016
I do get framerate issues as well, actually for example: towards the beginning of Escape from Stratis co-op, the framerate is pretty decent and playable but as we all progress towards the center of the island it slowly starts to tank until you're dealing with somewhat of a slideshow.
This happened both times I played the mission; a friend of mine seems to think there's a memory leak in the graphics department of the game because once you restart the game the framerate is back to tolerable speed.
Other people I've played with would also mention the frame rate drops as we progress further in the island.
Edit: I've added my DxDiag for any further analyzing.
Recoil is absolutely fine. However I've noticed that normally when you go prone, the LMG would have even less recoil, right?
Sometimes when I lay prone, maybe from a running sprint trying to get to low cover, the game seems to think I'm still standing because the recoil is all over the place even on my belly, so I have to correct it by standing up then laying prone again and the recoil compensation sort of fixes itself. Is this normal or is it just me?