Of late I will avail myself of this opportunity to make mention of this guide to Marksman spec Hunter through my own experience so as to share with all of you. if you take great interest in this, follow with me and see below:
   First thing first, weapon is a must. Since the Hunter is a ranged fighter, your ranged weapon is going to be one of the most important things. It should be noted that if you use guns, finding an engineer to make one for you can be very worthwhile. The ones made by engineers are usually much better than field drops and store bought, even up to level 60. As far as weapon stats go, there are two main types. Those with a relatively low damage per shot value but a high firing rate, and those with a high damage per shot value and a lower firing rate. As to which one you go with is up to your preferences. The pros and cons of each are as follows.
With a relatively low damage per shot value and high firing rate, the weapons are nice for several reasons. Since marksman spec increases your chance of getting critical hits, says that the more you fire, the more likely over time you are to get a critical hit. These are nice because when attacking casters, there is a better chance of delaying their cast, since each hit will set back their casting bar a little. A higher firing rate means that you can crank out stings and special shots faster, since their cool down is the same as your weapon and sometimes can deal just a little bit more damage before an approaching enemy gets inside your minimum range, meaning you might actually be able to take them down with your hand weapons.
Those weapons have two distinct disadvantages. One is that if we're increased damage abilities such as aimed shot and multi-shot, they don't do anywhere near as much damage as the high damage per shot weapons. This is amplified the critical hits. Another is the biggest. A weapon tends to have a firing rate almost double of its damage per shot counterparts, which means that you chew through ammo a lot faster. Without ammo, the Hunter is useless.
The ranges weapon you use is the ammo. For enemies that are common and have relatively low hp, the store bought ones are probably going to be enough, since you only use about 10 shots on each. However, things like bosses and plate armored players are a different story. Since these can take many shots and a very long time to take down, that extra damage conferred by the crafted ammo will stack up after time.
Pet is not quite important as to a beastmaster hunter. Still this is an essential part of a hunters fighting style. For marksman hunters, you typically want to find a pet with high damage giving ability. A marksman hunter causes some of the worst threat since they often do at least 1000 damage in the first few seconds of combat. You need a pet that can keep threat and do damage as well as possible, to keep the enemy focused on them and not on you. Now, you need to make sure your pet lasts longer as well. When it came to paying for the pets' abilities in training points, you should spend all in increased stamina and armor before taking type resistances. The straight melee damage is the most common damage your pet will take. After you have done this, put points into resistance for the most common types of spell damage that you run into. As usual the casters don't target pets with their spells that damage only one target, this is fire, frost, or arcane, as there aren't many shadow and nature area of effect spells.