Gravesend Mk 28

"We’ll show you how incredible it feels to see a Fallen Captain’s ethereal soul rip from its body after you’ve dusted his crew with your Gravesend Mk. 28 Heavy Machinegun . . .."

The Gravesend Mk 28 is a machine gun in Destiny. The weapon has not been described by Bungie, but has been very briefly mentioned in a Bungie news blog. No further information is available at this time.