Slowpoke problem, but... So I'm finding that since the changes in BoL that my ranger is having a tough time keeping up with other classes. I have been working to get the "right" rune sets and reforging to try and get to where the theoretical sweet spot is for DPS classes now. However, one thing I've seen fairly lacking is discussion of any changes in casting order. Have any abilities been changed so that they screw up the maintained DPS?
Try upgrading all your CAs and weapons. It makes a difference. Make sure you're always upgrading a spell. As a Ranger, I usually start with Snipe, Stalk (if I want to drag aggro and go stealth), or any of the non-stealth and non-behind-the-mob attacks. Your auto attack makes a huge difference too... Try timing your CAs to fit between auto attacks. Make sure your auto attack is in Forced Range/Spell. CAs... Just unload all the stealth and behind-the-mob attacks. (Sniper Shot, Rear Shot, Ranger's Blade, Sneak Attack, Hidden Shot, and others I might have missed) Put Focus Aim out whenever it's up before a pull. PFT for longer fights. Snipe is a good starter for all fights too. I like to use Cheap Shot if I'm taking a lot of damage because my Ranger is a backup tank for my group. Please note I'm not experienced in this... But this has been working really well and I can hit as hard as a Wizard. Hope this helps! If you have a casting order currently, I'd love to see it.
Don't worry about timing your CAs and auto-attacks. With BoL, they changed the mechanics so spells and CAs don't interrupt melee/ranged auto-attack, similar to how spell weapons have always worked.