61 Marksman

Specs
61 Marksman - 5 Nightblade - 10 Ranger
61 Marksman - 5 Nightblade - 10 Assassin *This spec will do higher damage when there are fewer target swaps ensuring you maintain 100% uptime on Magnify Pain e.g. Zaviel, Crucia. For fights with more frequent swap such as Progenitor 10 Ranger will pull ahead.

Buffs
Static Shock Munitions
Silver Tip Munitions
Predatory Instincts (10 Ranger)

Macros

Combo Point Builder Macro
#show empowered shot
suppressmacrofailures
cast empowered shot
cast swift shot
cast free recoil

Instant Finisher Macro
#show rapid fire shot
suppressmacrofailures
cast free recoil
cast rapid fire shot
cast hasted shot

DES Finisher Macro
#show deadeye shot
suppressmacrofailures
cast free recoil
cast rapid fire shot
cast deadeye shot
cast hasted shot

*Notice I have Free Recoil at the bottom of the builder whilst it is at the top of the finisher macros. The reasoning behind this is that putting it after your builders ensures it is fired between GCDs therefore not delaying any damage.

Other Action Bar Skills
Strafe
Decoy
Quick Reload
Deaden (Interrupt)
Eradicate (Purge)
Chain Destruction
Sentry Battery
On the Double (Runspeed Boost)

*Tip: Free Recoil is on a 12-second cooldown and lasts for 15 seconds so there is no way to waste it.

Single-Target Rotation
I only use Empowered Shot, Swift Shot, Free Recoil (except pre-pull), Bull's Eye and my finishers through macros. In the rotations below I have stated the actual skills used rather than macros so you get a better understanding of what is going on.

Standard Rotation
Empowered Shot -> Swift Shot x3 -> Finisher

Free Recoil Rotation
Empowered Shot -> Free Recoil -> Swift Shot x3 -> Instant-Finisher -> Empowered Shot -> Finisher

Cooldowns

Decoy
This is basically a 15-second damage-over-time ability that is also susceptible to all pet-damaging mechanics; yet it doesn't have any area effect damage reduction like standard pets do. It can be very annoying on a fight like Kyzan because not only will it die but it will be targeted by the Phase Rip mechanics. Unfortunately it does deal a lot of damage so we have to use it.
Key Buffs: Static Tip Munitions

Bull's Eye
With Living Energy (Chloromancer) or Anthem of Fervor (Bard) you want to use this with Empowered Shot. Without these skills you may prefer to use it with Deadeye Shot because otherwise you will find yourself energy starved if using many oGCD abilities in succession.
Key Buffs: Static Tip Munitions, Shoot to Kill (Empowered Shot)

Strafe
With so many instant casts and skills oGCD 61 Marksman can get energy starved very quickly. Strafe and Deadeye Shot are the means provided to prevent such. On top of that, each tick of Strafe deals more damage than Swift Shot. Typically I use strafe AFTER Deadeye Shot and let it channel until 3 combo points then clip with Empowered Shot. NEVER open with Strafe - not only will you have nothing to use for energy later but a hard-cast Empowered Shot + 3x Swift Shot builds combo points quicker anyway.
Key Buffs: Static Tip Munitions, Shoot to Kill

Quick Reload
Quite obviously the best time to use Quick Reload is when all of the above, Free Recoil and Rapid Fire shot are on cooldown. That said, it doesn't make sense to sit on Quick Reload for more than 10 seconds just to push out another Free Recoil, Strafe or Rapid Fire Shot. I do try to time Quick Reload such that I can push out 2x Free Recoils.

AoE Rotation
With targets lined up, Sentry Battery -> Sentry Battery (until 50 energy) -> Chain Destruction. You're clipping the second SB to avoid energy starvation. Without targets lined up just spam Chain Destruction.

Quick Self-Test
I have noticed a few people with good rotation, good gear and just not getting the numbers they should. Every time the problem has simply been not spamming abilities fast enough so here's a simple test:

1. Make sure you ability queue is set to Short or Full (Settings -> Interface -> Action Bars -> Ability Queue).
2. Use only the Combo Point Builder and Finisher macros and spam away on a dummy. No cooldowns.
3. Around 40 seconds you should be so energy starved that you cannot fire Empowered Shot.

If you take much longer to get starved or simply don't get starved at all contact me and I'll help you out.