COLLATERAL DAMAGE: 
Exotic Sniper Rifle 
"Critical Damage sustained. Please fire before it is too late." 
Intrinsic Perk: High Impact Rounds:
Sacrifice all the rounds in your magazine for a very powerful shot.
Corkscrew Rifling
Armor-Piercing Rounds
Exotic Perk: COLLATERAL DAMAGE:
Do more damage and gain faster handling while aiming down sights. Kills while aiming down sights heal you.
Rampage

Stats:
RPM: 30
Impact: 100
Range: 100
Stability: 15
Handling: 35
Reload Speed: 50
Magazine Size: 1

Notes: Using the Rally Barricade can bypass the one round limit, and would also benefit to Rampage. This weapon would shine at strikes, be trash in crucible, and probably be powerful in the Leviathan Raid.

Also, just so you know, I made this weapon thinking: How could you 1 phase Calus with just one weapon?