L85A2, and pretty much all the carbines still sound pretty shitty and weak. There have been a ton of posts in the past about this but I'll bring it up again since an update just happened. I'll go ahead and repost why this is again and offer a solution just in case the designers haven't seen it yet.
"If you notice, a lot of it has to do with the bass, which gives the gun a thump-like "kick". Compare the MK18 in the first game to this one and you'll notice what I mean immediately. A gunshot without a good treble/bass ratio can sound weak, muffled and like something is missing.
The reason I think they did this is because a higher rate of fire causes the bass to overlay and muddy the sounds of the gun and/or perhaps the environment out. Next time you play, do an experiment. Shoot the guns one by one from highest rate of fire to slowest. You'll notice, generally speaking, the lower the rate of fire, the more bass it has and the more full, meaty and high quality it sounds (this is probably why all the sniper rifles sound so sexy).
I imagine this could easily be fixed (I have some backround in music production so I think I'm at least somewhat qualified to speculate) by either shortening the tail end of the bass (this often is helpful in mixing/production when there are other bass sounds in the backround) and isolating the bass with EQ to allow the higher frequencies to shine through. So sound designers, if you're listening, that might be your solution."
Don't get angry at me creators. I'm doing this because I love you (sexually and emotionally).