Wesker, DMR's can easily be some of the most powerful weapons in the game when used correctly. Now first off you must realize that a DMR's idea "max" range is about 100 meters but this doesn't mean that it can't be used for CQ. Anything farther out then this will require 3 or more connecting shots to kill the target.
Read my CQ GUIDE: http://battlelog.battlefield.com/bf3/forum/threadview/2979150494248894038/
Beyond all of that remember a few things...
1) DMR's are not made for extreme ranged sniping as the damage drop off becomes too severe at ranges requiring a scope.
2) Most always a holo-sight or similar recticle is preferred as it allows you to see more of what's going on while staying focusing in on the target. With this you can see and judge the rate of bullet drop as well as react faster to what's going on around you. Besides anything larger then a x4 scope will give away your position due to scope glint.
3) DMR's first two - three shots have manageable recoil and as such you should be firing in short bursts to keep your accuracy spot on.
4) Bipods are largely useless in 90% > of the confrontations your likely to encounter. Let's face it, by the time you've set it up its most likely too late to be of any use.
5) For longer ranged attacks I'd suggest the EMR but for CQ, the M417 is a beast! The SKS is really for those that would be better off playing the Assault class.
6) There is never any reason not to use a suppressor.
7) Don't play like a bush-Wookie as the DMR is designed for a more aggressive stile of play. Instead play like an assault, get in your enemies face or better yet flank them!
8) Aim for the area at the top of the sternum or just below the neck. In many cases, the first shots recoil will raise the second for a head shot.
9) Surpression is your friend... Use it to keep enemies from counter attacking effectively.