Compression phaser rifles are among the most powerful personnel-carried weapons in the Starfleet arsenal, and are an alternative to the type 3-phaser rifle. These powerful weapons are assigned to starships that could possibly see intense close-quarters or surface combat. When set to wide beam, they could fire over a large area potentially taking out a large group of individuals in one shot.
The USS Voyager was equipped with compression rifles as a standard part of its weapons inventory. They were first used by an away team which transported to the Caretaker's array in 2371.
The USS Equinox was also equipped with them in 2371, as several were still used in 2376 shortly before the ship's destruction.
The compression rifle was also the standard armament for Hazard team members aboard Voyager from 2376 until the ship's return to the Alpha Quadrant.
On more hazardous missions, Starfleet officers carried the compression rifle as a greater source of firepower. The rifle fired pulses of a similar but more powerful type to the phaser in a tight beam. The compression rifle also fired a more deadly and silent sniper shot, which required more energy but could be very effective on infiltration missions.