This guide is just to give a brief jumpstart or reference to anyone interested in running a Commando in endgame PvE, or advice for existing Commando DPS that are familiar with their class. The guide is based on personal experience and odawgg's guide. If you're looking for an updated and advanced guide that includes rotations and priority systems, I'd highly recommend odawgg's guide.

1.0 Specializations
These specs are my most recommended and will produce the highest DPS while parsing on a dummy.

Gunnery - 6/36/4
Assault - 0/10/36*
*When parsing on a dummy, you can forego the two points in Steadied Aim and place them in Field Training instead.

1.1 Specs Based on Encounter
The following list details which specialization is best suited for each encounter to produce the highest DPS. Some choices depend on your role in the fight or group composition, for example if you're kiting Raptus or not during the Dread Council fight.

Note: Just because one spec is better suited for an encounter than another doesn't mean you have to play it, especially if you're not familiar with more than one spec. The spec that's better for the encounter isn't any good if you don't know how to play it as well as another.

Dread Fortress
Nefra - Assault
Draxus - Gunnery
Grob'thok - Assault
Corruptor Zero - Gunnery
Brontes - Gunnery

Dread Palace
Bestia - If on Dread Monsters Assault; if on Dread Larva Gunnery
Tyrans - Assault
Calpayhus - Gunnery
Raptus - Assault
Dread Council - If kiting Raptus Assault; if not kiting Raptus and group needs an armor debuff Gunnery

2.0 Gear

• Augments: Use Reflex.
  
• Critical Rating: 240 is ideal for both DPS specs, but anything between 200-360 critical rating is acceptable without noticing a big difference in DPS. I typically get near 240 with two critical mods and enhancements as they're easy to come by.
  
• Accuracy Rating: 470 is the goal, deviating from this number will show larger disparities in DPS. I achieve this through accuracy implants and enhancements, but going just enhancements works as well.
  
• Power/Surge: These come after you've obtained the desired critical rating and accuracy rating. Fill what's left with these stats.
  

3.0 Rotation
This is just my opener and basic rotation. I'll add Assault later when I become more comfortable with the spec.

Gunnery

Opener:
Tech Override** + Grav Round > Grav Round > Relic/Adrenal + High Impact Bolt > Demolition Round > Electro Net > Full Auto*** > Begin Rotation

**Only use Tech Override on static fights (aka no movement encounters like dummy parsing), otherwise save it for movement phases to sustain DPS. When parsing on the dummy, use Tech Override when you have a lot of energy.
***Only Full Auto if Curtain of Fire is procc'd, otherwise continue Grav Rounds until it procs.

Rotation Rules:

The best way to cover the rotation is just to keep a general set of rules in mind:

1. Never use High Impact Bolt with less than four stacks of Charged Barrels (i.e. two Grav Rounds before High Impact Bolt if off CD is mandatory). With practice, you'll find gaining 5 stacks (using three Grav Rounds before High Impact Bolt) an easy task to manage.
   
2. Never use Demolition Round on a target not affected by your Grav Round. The DPS loss is substantial considering the cooldown on Demolition Round.
   
3. Keep High Impact Bolt and Demolition Round on cooldown. The amount of damage they do per energy spent is massive and while they aren't the bulk of your DPS, they are a primary contributor.
   
4. Try to keep Demolition Round immediately after High Impact Bolt. They share an identical cooldown and doing this will keep them in line with the cooldown on your relic, adrenal, and Electro Net giving you greater burst potential.
   
5. Try to only use Full Auto when Curtain of Fire procs. This isn't always possible due to bad luck, but keep in mind that prolonging Curtain of Fire procs means a DPS loss, and casting a non-Curtain of Fire Full Auto wastes a lot of time that could be used for proccing Curtain of Fire. I would only recommend casting a non-Curtain of Fire Full Auto if you're running low on energy as Full Auto is an energy positive ability (as long as you stay in the top tier of energy regeneration).
   
6. Using Reserve Power Cell and Recharge Cells on cooldown will help to maximize DPS, but don't attempt this while you're just getting used to energy management. I'd also save abilities like Recharge Cells for moderately long burn phases for enhanced DPS during encounters.
   
7. Between High Impact Bolts you should have one or two GCDs of filler if Curtain of Fire is cooperating. One of these fillers should be devoted to Hammer Shot to maintain energy in the upper threshold. This can come before or after a series of Grav Rounds or Full Auto, but just keep in mind that using too many Hammer Shots will result in a DPS loss.
   

If there is anything else you'd like to see in here let me know.