Dual Shot will surpass Shield Piercing with medium sb above 40 if I can recall correctly (maybe 42, can't remember... ask DM ^^).
I haven't tested them accurately but here goes what I remember. Tear Apart (5) + normal will remove mages nasty barrier in most cases (namely lvl4 barrier), it will kill a knight that relies on troll skin to get away on fort wars, it will kill an archer that relies on LP too late, it will kill a conjurer that saved sanctuary to the last minute... it's just awesome! Break Apart it's very good too, 20 const is an equivalent to nearly 420hp, but the direct dmg is lower (the 20 const penalty is instant and it will rock at fort wars... add it with crushing from a warrior friend and it will be a nightmare for the poor fellow) but the most important issue is casting time! And being a hunter is all about being fast (that's what annoys people), fast speed, fast evasion, fast casting, fast dmg and range isn't an issue if you land the 1st shot (camu, stalker, trickster all the way!)... the only slow thing you need to have is... a pet! (if you want to play with pet setup!)
As a hunter you will use 3 dmg dealing spells most of the time (dual, ensnaring, tear), 1 when you feel that the terror was well placed (or when you feel like lvling faster, or when you feel like killing 4 grinding adversaries AT THE SAME TIME is the coolest thing you ever done before, or if you party up with other 3 or 4 crazed hunters and you want to end that fort war quickly... <ninja> way!), 1 circumstantially (grounding arrow) to shorten base evasion and archers base dmg.
Always have AT LEAST 3 bows, sb fast (buffing, drop area and LP/tear apart after or whatever you think it's appropriated, cancel camu and "sometimes"... RUN!), sb medium (your personal uzy... you'll get them with range 25, not sure what lvl though), and (my choice) long slow bow (xym preferably) to teach marks who are the true archers around here... although they have a nasty passive that increases range we all know who puts points in evasion and never forgets to buff don't we?
Now, for lvling at your lvl, probably a long with shield piercing and a pet, get 2 long bows, use the slow 1st to hit ensnaring (more dmg) then switch to medium for dmg dealing and power casting. It's a pity you are a goat (
), I just dropped a xym medium short for lvl 34.
And now to bed, there are higher lvl hunters around here that will correct/add something on what I said (and I'm glad they'll do it cuz I've much to learn yet).
Have fun
