"Ancient pattern military sniper rifle. Bolt action. Long range, great accuracy and power."
An 'upgraded' version of the Survival Rifle. It fares worse in close-quarter combat compared to the Survival Rifle, but has better qualities regarding range and power.
The Sniper Rifle currently has the longest range out of all of the guns in the game, as well as the highest damage. Its only real drawback is the long warm-up time between shots, making it less than ideal when the position of the shooter is under fire. Make sure your marksmen are well-covered by turrets or close combat troops. Also remember that raiders often carry these with them when they go on attacks or sieges on your colony, so be very careful of enemy snipers. Consider designing your defenses accordingly to eliminate positions where raiders could safely sit and take shots at your colonists.
This weapon is powerful enough to destroy limbs in one hit, which makes it a very useful weapon for killing raiders at extremely long ranges. This does mean, however, that if you plan to capture enemies and turn them to your side, you may find yourself burning through your stock of replacement arms and legs rather quickly to try and patch them up -- if they even survive at all, that is.
The Sniper Rifle is also a valued tool for defending against siege attacks. Not only can you attack enemies preemptively and potentially kill several before they get close enough to fight back, but you can also target their artillery shells and mortars in their camp, causing them to explode, damaging or killing anyone nearby, and potentially starting a wildfire. In the latter case, the fire alone can wipe out the whole camp if the raiders don't move.