Need d20 stats for this weapon

[Lemur]

My take:

Skorotsnoy Industries RPC (Rocket Propelled Chainsaw)

Heavy Weapon (Requires Exotic Weapon Proficiency: Rocket Chainsaw Launcher)
Damage: 3d8 slashing
Crit Range: 19-20
Rate of Fire: 1
Range: 100 ft.
Magazine: 1 internal
Size: Large
Weight: 13 lbs
Purchase DC: 24
Restriction: Illegal (+4)

The RPC is a one use weapon that fires a specialized rocket chainsaw at a target at high velocity. The chainsaw rocket itself cannot be used for normal chainsaw purposes if removed from the launcher.

Edit:
There are rumors that an advanced prototype exists. Such a weapon would have a laser guidence system (+1 equipment bonus to attack roles) and would allow the user to make any iterative attacks he has available against secondary targets behind the original target. Any given target may only be attacked once in this way, and must all stand in a straight line from the weapon's firing point. The normal penalties for iterative attacks, and any additional range penalties accrued by traveling between targets applies.