A Chaplain's standard weapon is the Crozius Arcanum: a close combat melee power weapon which is designed to discharge its energy on contact and inflict damage on even armored targets. It's not a ranged weapon, suggesting that Carnaks was a unique piece of wargear with special abilities (a common thing in the WH40K universe)
Severus: Chaos breaks men's souls. Chaos brings the pestilence of daemons. Every time we march from our beloved fortress home on Macragge, we march to face down Chaos, and banish it. Do you think you are ready to do that, Proteus?