[Claudius]

It could be your setup too. Hunting can kill bosses quite handily as long as you can stay alive. Do you have Call of the Hunt + synergy. Combine that with Study Prey which is worth maxing eventually. You can do a lot of pierce with that setup because damage resistance is multiplicative with piercing buff not additive.

Math:

For each 100 piercing damage..

100 x 1.15 (because your attacking 15% faster - level on call of hunt) x 1.6 (because level 1 COH synergy) x 1.5 (for maxed Study Prey) = 276

So with 10 skill points you have tripled the damage that passes through armor. Study prey is even more important against pierce resistant. Example a 80% resistant monster only takes 20 piercing damage (I'm not including Call of Hunt..) in above example but with study prey active it is only 30% resistant and takes 70 points of damage which means study prey alone caused almost 4x the piercing damage. And since its multiplicative with Call of Hunt it does 6x or 7x the damage compaired to not using the skills. Much more if you have gear and art of hunt.

The first two terms are more if you have other gear.

Edit: as you can see its important to get piercing damage for this to work so stick to bows and spears with a hunter