Necrotic bone in Monster(1.0.9)

[gago]

Hello!

I'm playing ftb monster on a server and i've been killing wither skeletons a lot(mostly from skeleton spawners brought into the nether, but quite a few naturally spawned as well).
In all of these kills i have gotten no necrotic bones. Is that a bug or are they just insanely rare?

I was using cleaver with beheading and fortune or a tinker's broadsword with fortune.

Take care,
gago

 

[Bellaabzug21]

They're just insanely rare.

 

[ThatOneSlowking]

They're just insanely rare.

Which version is in monster? In a modified FTBLite2 server im on they drop like crazy
I got one wither head

 

[gago]

I've been killing them some more, getting a bunch of wither heads, lots of other drops, even a couple emeralds from those "boss" monsters. No necrotic bones..
I guess it's not even worth farming them atm since they're so rare.