Sorry to bump, but I thought I'd add a bit of input from the practical standpoint.
A suppressor is used on a weapon to reduce (to a degree) the noise of the weapon, which in CQB is very disorienting (get a real rifle some time, open a window, close the doors, pull the trigger and behold). To get that truly "quiet" effect we see in Hollywood all the time, you really need to use subsonic ammunition. While a suppressor will dampen some of the noise involved in exploding powders (nose will still vibrate through the chamber, however), once a bullet hits sonic speeds it will crack as it breaks the sound barrier. Unfortunately, subsonic ammunition does not have the gas output required to cycle most semiautomatic or automatic weapons. Here is a video:
That being said, putting a silencer on the bolt action DSG-1 would be a tad pointless -- you would have to lower the round velocity considerably, losing rang, accuracy, and overall stopping power.
In the case that the above video refuses to work: http://youtube.com/watch?v=PEoh-MmpJNM