Are you playing an Infiltrator or a Soldier? If so, you have the tools needed to make Sniper Rifles work for you. Infiltrators can use Tactical Cloak to position themselves strategically to take out opponents from long ranges, and line up a perfect shot unnoticed. Soldiers meanwhile, can use Sniper Rifles to open an engagement, as well as shooting from the hip with them to get a little bit of extra punch against armored opponents.
Keep in mind, Sniper Rifles are still quite good, even at fairly short ranges, because they allow for a great deal of precision when you fire, have high armor penetration, and time dilation makes it easy to line up headshots against small targets like the soft points on Brutes and Guardians.
Playing anything else? The added weight is probably not worth it - without the time dilation benefit that Soldiers and Infiltrators can gain, it's difficult to line up a shot on a moving target under fire - getting off one round isn't worth the additional recharge time to a Vanguard, Adept, Engineer or Sentinel.