The suppressor is of limited use on the XPR-50 as keeping off the radar is only important if you are close to enemies. Maneuver the map so that you are unlikely to run into enemies towards positions where you have cover and be ready for enemies out in the open. When you are changing position pull out your secondary as it is much better at close quarter engagements than the XPR-50, but such fights should be avoided since most secondaries are inferior to the primary weapons suited to close range engagements.
But don’t stay in the same place for long, frequently change positions to a new location that overlooks a high traffic area or a choke point. However, the slow handling characteristics and long aim down sight time of the XPR-50 mean that the rifle has to be used more passively in a defensive position. It is a semi-automatic rifle which is more forgiving to missing with a shot than the bolt action sniper rifles. The XPR-50 is the last sniper rifle you unlock in Black Ops 2 at level 52.