For the Devour proc it says, “Devour (100% Chance on Critical Attack) Upon landing a vicious blow, devour some of your foe’s exposed life essence.” That sounds like a melee attack from the text, but that is not indicated otherwise. Does it work with spells? It also says 1 target maximum, so if I proc it again on another enemy does it cancel the first proc, or does it proc only one enemy at a time? I am considering using it on a bleed/vit caster, but the proc is a big factor in comparing it to a few other weapons.
It should work with spells too, just like all other “on crit” effects. Every time you deal a crit (and skill not on CD), it will be triggered. Crits from DoTs might be ignored (though i’m not sure, needs testing).
Not sure about range.
“1 target maximum” means that proc affects only one target. It can be another target, that the one you delivered critical hit, though usually, it will be the same target (just the same as with all other procs, i think).
For vitality caster, that proc is useless. Vitality casters have tons of other procs with “ADCTH” effect, from constellations, items and even primary skills. Another proc wont add anything really useful.
For bleed build, however, proc can be really useful. It not only adds significant bleed damage, but also has ridiculous amount of %ADCTH. Even considering it deals only 30% weapon damage, and damage from attack for bleed build wont be high, 300% ADCTH (!!!) can provide significant sustain, considering that bleed damage cant use ADCTH.
20% armour piercing also mean that it’s not a weapon for physical build.
So obviously, Butcher of Burrwitch is designed for bleed builds. Everything in that item screams about that.
Good to know. I think I will likely use it or Ravager’s Bite on my caster. I am using a mix of bleed and vit damage and it has been really effective so far. I have been stacking lots of on hit and on critical procs with lots of -res which work nicely with my multihit aoe attacks.
I wonder if it does ignore dots, I will have to test on the dummies. That won’t be a big deal since a lot of my dot like attacks are actually normal vit damage.
That stinks if it can only be applied to one target at any given time. I wondered if that meant it would only apply to one target per proc but could apply to other targets too with subsequent procs. Still pretty effective.
Ok, so I removed my other proc items and tested it with both wendigo totem and eye of dreeg against both regular enemies and the dummies and it doesn’t seem to work with spells 
I had the multipliers displaying so I know I was getting crits. So, it looks like the Butcher of Burrwitch is scrapped for my caster build. I wish it would be clearly stated that it doesn’t work outside of regular attacks in non flavor text. Now do I go with the Barrowholm pistol or Ravager’s Bite, decisions decisions.
Its cast range will be updated in v1.0.5.0. It does work with spells, but presently has a melee cast range.
Ohhhh ok. Sweet! That might make it my top choice again. What about number of affected targets? I wasn’t sure how that worked. Thanks for the info!
Even with 1 target, it will be far stronger, if range will be increased. Dont forget, that various ticks from things like Grasping Vines or Devouring Swarm can also trigger that.
What? But only the Vitality/Physical part of the damage, right?
That would be awesome…and perhaps BiS for my Bleeding Trickster for ADCTH.
Oh for sure. I just wonder if the description means it will only apply itself to one target per proc or if it means only one monster can be under its effect at a time. I suppose the bleeding damage could be on multiple targets at the same time as the attack overall doesn’t have a duration. The cd is really low so even with the low weapon damage part you could still be dishing out quite a bit of damage. Any way you slice it though I think it will be bis for the build I am working on which includes the skills you mentioned.
Isnt that enough? Those skills tick every second, and affect multiple enemies.
Sure, 1 target per proc. But CD is very low, so if many targets are affected by things like Grasping Vines/Devouring Swarm, and you have high OA, devour will proc often.
As i already said, Burcher of Burrwitch is a weapon, specifically designed for bleed builds.
Isnt that enough? Those skills tick every second, and affect multiple enemies.
I know, I have this skills. 
Question:
30 % Weapon Damage…so this means they will tick for 87,50,33(=78,75)*Crit-Multiplier each time? (87,5=(67+108)/2)
I am excited to try this out post patch. I really like that the item gives an all damage buff too. That works well for me. I appreciate all the input everyone has given.
Hope the Brutalax proc gets this treatment as well.
For anyone curious, this is the build I am planning to use Butcher of Burrwitch for: http://www.grimdawn.com/forums/showthread.php?t=67949