GearArmorThe desirable properties for Marksmen are +stat/+AA (All Attributes) for reduced feeds and thus more cdb (critical damage bonus),+crit chance from specific uniques/set pieces,+duration of boost skills (
Multishot) and the rarer +armor penetration.Therefore,the two most usual armor choices are:
1)
The full Infiltrator set,possibly with a few +stat/+AA augments.Unlike most classes,where the usefulness of a full set is debatable,the Marksman's set is unquestionably powerful.Unfortunately,it's also rather expensive.
Pros: It provides base crit chance,a considerable +use rate of boost/tactical skills,armor penetration,movement speed,a +1 to a random skill through the set legs,an incredible +100% cdb and a
+1 to all Marksman skills without the nasty feeds that it otherwise comes with.Its total feeds are rather reasonable.
Cons: The Infiltrator set may be the most expensive set in the game,thus it may be quite a task to assemble one.Some pieces,such as the torso or gloves,are nothing special as individual pieces and only really contribute to the full set bonuses,or if +stat/+AA properties are augmented on them.
2) A combination of 3 to 5 set pieces and uniques/stat pieces.This choice most often includes
the Eyes of the Maverick helm,the
Grimsoles boots,the
Duellos of the Duelist gloves and the
Infiltrator belt/
shoulders (or the
Forgotten Warrior/
Lazy Envoy miniset belts for armor penetration),in an effort to get as much base crit out of armor as possible.The other pieces may vary,depending on what set bonus players are after.
Pros: Most such gear combinations should be relatively/much cheaper than a full set,even more so than a properly augmented one.They should also still be quite effective in terms of damage,as base crit and similar bonuses are still obtained.
Cons: If one is after the +1 to all skills property,augmenting it on either an Eyes of the Maverick or a set helm should be quite rare and expensive.This property also comes with heavy feeds.
Moreover,dedicated Marksmen have concluded that any such combination is most likely inferior to a full Infiltrator set in terms of damage.While augments may cause the numbers to vary somewhat,it's most often agreed on that the full set is mathematically the superior choice.
WeaponsMarksmen are curiously among the very few classes that actually have a choice among roughly equally effective weapons in endgame.Those choices are:
1) Dual
Hu's HypershotsThose become available as early as at level 43,and they appear to provide the 2nd best base damage out of all listed options.Unfortunately they lack +base crit,so a +3 crit and a +desired ccm (crit chance multiplier) or +desired cdb (critical damage bonus) augments are essential for these guns.Lastly,their item level may render it harder to find appropriate mods in comparison to the other weapons listed.
2) Dual
HurricanesThese machine pistols provide good base damage,and also provide the very useful +crit and +boost skill duration properties.They also provide
a total of 46 points in Beacon if one wishes to save said points for other skills.Lastly,due to their item level,it is relatively easier to find appropriate mods for them than Hu's Hypershots,for instance.
3)
Person of ThorThis twister gun has quite decent base damage,and is most often preferred for the Land of Rest.It has an innate 3% crit and an added 13% as a property,plus 1620% added Spectral damage.It is the easiest weapon to find mods for,as both the item level and mod types are quite convenient.
4)
Z83 Gatling Rail CannonsAll Gatlings have rather good base damage,a standard 5% base crit chance and 200% cdb,which is 100% higher than Person of Thor.These Mythicgrade weapons naturally come with random properties,so their actual efficiency varies somewhat.The best Gatlings should roughly come with

2x (/3x) elemental damages
% desired caste cdband possibly
% desired ccm and
+base crit.
Most other properties come with needless feeds which eventually cost in terms of damage,and therefore should be avoided.
ModificationsThe most efficient mods for Marksmen are,unsurprisingly,dual +ele/ccm and +ele/cdb ones.
The usual modding priorities for all damagedealers are,roughly:
1) Ccm against a desired caste until ~9095% crit chance against that caste has been secured
2) As much cdb against the same desired caste as possible,and
3) +elemental damages amassed from both the ccm and cdb mods.Depending on available feeds,Marksmen seem to benefit most from higher +ele damages on dual mods,in spite of the relatively higher Willpower feeds.
In the case of Marksmen,the base crit possible requires far less +ccm mods than classes such as Evokers.In general,Marksmen should require 2 to 3 ccm mods to reach the required crit chance
on weapons with no ccm on them.The number may decrease further depending on one's total base crit and +ccm augments on weapons,possibly even down to 0 if one has enough base crit and uses a Gatling with 2x ccm properties.This leaves respective room for +cdb mods,in effect drastically increasing the maximum damage possible.