To start off you have 2 snipers to work with until level 36. So you need to choose one of these snipers to use and which one suits your playing style best. Here are the snipers and a brief description.

Intervention-Great bolt action sniper rifle with a medium sized magazine, extremely accurate and medium to long range. It has some kick but not to much. I believe the clip size is 5 bullets, correct me if im wrong =). Fire rate is a little slower because of the fact that it is a bolt action sniper rifle and not semi automatic.
Barret .50 Cal-This sniper rifle IS semi automatic with a fairly large magazine. I do want to point out that this sniper seems to have more kick than the intervention and it is a lot less accurate because of that. It has a pretty good fire rate but im afraid the faster you shoot it the more kick and less accurate it gets. =(
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The next two sniper rifles come from the same type of sniper. They are both very accurate and have a very high rate of fire.

Wa2000 (LVL 36)-This sniper rifle looks a little odd and maybe a tad wimpy but don't let looks deceive you. This sniper rifle may not have high fire power but it definitely makes it up in its high rate of fire, and accuracy.Be sure to know if you shoot someone with this sniper rifle then it WILL hit the almost exact spot you shot it at. As i said before the fire power is sort of wimpy though. With no attachment pertaining to the barrel or the FMJ (full metal jacket) bullet penetration, it will take 1 or 2 sloppy shots to take down the opposition. If you have a silencer attached then expect it to be 2 well placed shots almost every time except if you hit them in the head.
M21 EBR (LVL 56)-Some of you may remember this sniper from Cod4 modern warfare. This sniper is almost exactly like the Wa2000, in that it has about the same rate of fire and damage. This sniper is a great choice for those who like to do more of the "sneaky approach" to sniping. Ex. getting in your favorite spot with a silencer and thermal attached to your sniper rifle.

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Now that your familiar with the snipers you have to choose from, i will explain the approaches you can have to sniping.

First off, is what i like to call the "sneaky approach". With the "sneaky approach" you would use a silencer and if wanted the thermal scope. The silencer will hide you from enemies on radar. This means that they can't see you on their radar when you shoot from your sniper. This approach also uses a technique i like to call "no peeking". haha funny name huh? Let me explain, i like to call it "no peeking" because as you all know; when you kill an enemy they can see you on the kill cam. The "no peeking" method is when you snipe someone, you stay in scope for 1 or 2 seconds after you kill your enemy. This will hide your position to your enemy and prevent them from trying to look for you the next time they spawn. This is fairly effective but you still want to make sure to watch your back, because it doesn't work all the time. Some people are able to find out where you are using angles and the surroundings they see through your scope as you are sniping them. Thats why the next part is also very important.

Choosing the place you snipe can make all the difference in the world when it comes to kill streaks. You want to place yourself in a position where you are able to see almost all around you without them being able to see where you are. These spots are usually behind or in shrubbery. However if you are hiding in or behind shrubbery you DO want to make sure that there are no leafs in the way of your scope. This is not because it restricts your view, but rather when your enemy is watching your kill cam you don't want anything and i mean anything giving your position away. This will help them so much more if they see leaves in your scope, they will be able to tell that you are in or near shrubbery and lets face it, there are not very many bushes or shrubs in many of the maps except for wasteland. This will help them to narrow down where you are and will help them to find you faster.

The next and final method i have for you is the "here i am" method. This method can and will make you laugh if you pull it off correctly. For this method, it doesn't matter at all what your attachments are. This is because you are telling them where you are almost every time. This method works best in more of the urban environments, because your going to be hopping around a lot. With this method, what you want to do is hide in a fairly good sniping spot with a very good get away area where you can go and watch the previous spot you were at. This means that when you snipe someone you don't have to use the "no peeking" method. When you snipe a fair amount of people (2-3) then you want to relocate. Preferably an adjacent building or area that you can watch the previous area you were at without giving away your current position. Then when the enemy goes back to your previous spot (trust me, they will; there are a lot of noobs in this game that spend wayyy to much time in kill cam). You can snipe their face off and say "BAM! Here i am!". *you want to repeat this method for it to be effective, but remember the more times you relocate, the higher chance you have of getting killed*


Since we now have the methods down, im going to move on to perks.

Perk 1- You either want to have Sleight of Hand Pro, Bling, or Scavenger Pro
Sleight of Hand Pro-The reason you need sleight of hand pro and not sleight of hand, is because you need the faster ADS (aim down sight) for those of you who like to quick scope like me =)
Bling-Everyone knows you get two weapon attachments...self explanatory, you can use thermal with a silencer if you please. Or other weapon attachments for that matter.
Scavenger Pro-You need Scavenger Pro, and not Scavenger because Scavenger Pro gives you extra clips right off the bat and you don't have to go searching for them, which lets face it, when your sniping you never want to compromise your hiding spot to go out and get a couple of mags.

Perk 2-The only perk i really recommend is Stopping Power
Stopping Power-Increased bullet damage, a well placed shot can and will take down your opponent.

Perk 3- Along with Perk 2, the only thing i really recommend is Steady Aim Pro
Steady Aim Pro-Increased hip fire accuracy (doesn't really help while sniping but def helps with your secondary to protect yourself from people trying to sneak up behind you) Also gives you "iron lungs"<<<Cod4 reference LOL, anyway what this does, is it lets you hold your breath for longer while sniping.

Death streak-For death streak i like to use Final Stand or Painkiller while sniping.
Final Stand-if an enemy sniper, snipes you then you get knocked to the ground and can stand back up and snipe them!
Painkiller-if your getting spawn trapped then this comes in handy, and its not like juggernaut...this is like juggernaut on steroids, thats why you only get 10 seconds of Painkiller...

To conclude this segment i would like to end with Killstreaks.

If your going for a nuke, then i would advise using-

Harrier Strike
Chopper Gunner/AC130
Nuke

Harrier Strike-not only do you get a sort of "precision air strike" but you also get a hovering aircraft that is extremely effective if well placed. After you get this then you can pretty much hide and let it go to work until you get the Chopper Gunner/AC130.

Chopper Gunner-This is what i use for my 11 kill streak reward, mainly because it can move around the map according to where the enemy is instead of flying in circles. Also you can just hold down the trigger and go to town.

AC130-I would rather recommend the Chopper Gunner than this because the AC130 is good, but you can't get close enough to be precise on your shots.

Nuke-Endgame, your the king of the lobby and you will feel like your on top of the world =)

Thats my simple guide and i hope it helped some of you!
my gt is my skill is sik if u have any questions Rep if helped