I have Blessed Whetstone and Nidalla’s bonus, so I’m at %150 on my Pierce/Bleed BM. Sadly I still do not have a reaver’s claw in spite of the fact I have a dozen each of most legendary swords. Bloodsong looks ok but the piercing is lousy.
Anyway, I thought I spied at some point another source of piercing conversion, but I’ve since forgotten. Perhaps on a piece of gear. Thoughts?
Devotion blades of Nadaan +100% to pierce conversion.
Afaik there is no phys to pierce conversion on other gear except weapon or 2pc Valdun set bonus.
I mean to say Nidaan, not Nidalla.
Ok, found it. “Sinister” prefix on swords. Can someone explain to me how the “+% armor piercing” stat granted by this prefix works? It is an additional stat to the first %piercing stat on the weapon. Would it apply to both weapons as a Blessed Whetstone does, or just the one weapon it’s on?
Sword is weapon 
If you for example have sword with 33% to AP, blades on Nadaan will increase it to 66% AP and if you get sinister with 100% to pierce it will make your conversion 99% to pierce. This was example I dont think is possible to get 100% AP from sinister. It works for both weapons like blessed whetstone.
Sinister can have 120% pierce conversion.
Are you sure, its a huge deviation, best I could find was 82%?
I found one/ Crafted one. Found several over 100%. I don’t think the numbers are accurate in Graceful dusk.
I bulk crafted exalted butcher, was thinking that armor piercing increase from sinister is additive, and that 25% base AP from butcher + AP from sinister will make it pure pierce, got few ones and highest was 82% if I remember correctly. But that was some ~5 months ago and maybe is just my famous RNG luck 
I was very suprised as well. i found/ crafted many with the same resuts as yours and thought i wouldn’t be able to make normal swords, not slicers, be 100% pure pierce. It seems it is possible.
The actual piercing cannot exceed 100% of listed flat damage dealt though, regardless of the bonus, correct? For example, if the weapon’s flat damage max is 100, you are not ever going to deal more than 100 piercing damage you are never going to deal 101 or more damage via piercing conversion.
Yes, you can convert 100%, everything above that does not count, its the same with every dmg conversion.