Highest possible damage on a weapon & Leap attack

What is highest possible damage on a weapon?

I mean min - max dmg, not dps.

Is it some Eth unique or a rare with epic affix rolls?

Also, need confirmation about how Leap Attack works - it doesnt need ias since its fixed duration? So ideally, when making a build centered around it, you want such weapon - slow but heavy hitting.

As far as I know it is an ethereal Rune Master socketed with Ohm runes + Zod.

1 hand weapons
ethereal RM with perf roll and 4 ohms = 349 average damage

lowest roll Grief in a PB = 371 average damage ¯\_(ツ)_/¯

2 hand weapon
botd in sup ethereal Thunder Maul and perf roll = 823 average damage

The Cranium Basher is also decent despite its str requirement, the 75% CB with amp and all res are nice, I killed a Dclone using this on a Leap Attack barb 7 months ago. A Death Weapon 2h is also a good option

As you are ignoring speed, If you consider Deadly Strike and are looking only to the weapon:

- Death will surpass Breath of the Dying on the 2 hand category.
- On the 1 hand category... ... perfect x perfect, I think Grief will still win by a little over Death (remember that Grief have 20% DS and that ignoring speed you could use a Ettin Axe for the Grief - if you you have the runes to throw away )
- And Rune Master will deal more damage with some Lo instead of Ohm

But in the real world... DS on weapon will have less effect if you have DS (or equivalent like Critical Strike) on other equipment or Skills so the calculation is not that simple...
(In special, most of the attack builds use Highlord's Wrath which have DS too...)