This mod is set in Games Workshop's, great Warhammer 40,000 ( 40k ) universe. Each map pits Imperial Space Marines against the Tyranid swarm, competing in a series of mission objectives, culminating in a battle to decide the fate of the planet. Latest scheduled play times and list of servers: steamcommunity.com/groups/exterminatusgame
One on one the Tyranid Warriors "Deathspitter" weapon is not much of a match for the Tactical marine's boltgun, it's splash damage barely making up for it's slow rate of fire and lack of accuracy.
Against a tightly clustered group of marines, it can be quite effective. As seen here on Ichar IV.