speedy80 wrote STEP 1 : Understanding Hitboxes & Hit Registration
These terms are slightly discussed above, but I will go more in depth here.

Have you ever shot someone around a corner? Have you ever shot 5 feet behind a running target and killed him ? Have you ever fired in front of a target and killed them? Have you ever shot, on a laggy server, right on a walking target and couldn’t kill him? Those are all due to hitboxes.

Hit Boxes in Modern Warfare 2 are a box, whether it be around the whole body or around body parts (MW2 has a gap in between legs, but when sniping you’ll rarely notice this). If a bullet comes into contact within the box you will get a Hit Registration – and hopefully a kill. Basically, its what I some times call the target box… Being shooting at it gives you the kills. When a target moves – the box lags or drags a bit behind his movement. Example; Guy runs right – his hitbox is to his left, behind him. Now, when someone comes to a COMPLETE stop, or changes direction… The hitbox will slide from behind him, to in front of him, and then slowly move right around the body of the target (if he does not move). This is why hitting Zig Zags are hard, cause the hitbox is behind him, and by the time you shoot there, he stops and it gets ‘thrown’ in front of him, as you shoot behind.

Warning: Lag will increase the distance of boxes FROM the body, I’ve had such bad lag before – That I had to consistently shoot 5 feet behind people to kill them.

Have you ever shot and got hit reg but not a kill ? Have you ever fired multiple shots and cant land it – even though he’s sitting still? Ever have a full on, 100% sure shot – that doesn’t hit? That’**** registration for you.

Hit registration is the game accepting your shot as a shot ON TARGET. Which means, hit markers. Now, hitboxes with lag move position… BUT! The lag also effects hit registration. Sometimes, the game will show that you fired on your screen, but not on theirs. That’s what we call, bad hit registration / lag. Also, when shooting a sitting still target – and nothing seems to hit him – either you suck at aiming or the servers hit registration is really poor – which normally means a bad host upload speed, or server to you is not synced very well… Which happens.

STEP 2 : Picking Your Rifle
First and foremost lets pick you a rifle, at the end of the list I will give you my opinion.

* Intervention – Good for quick scoping, no scoping. Good with thermal (has camo on Thermal). Bad or Large breathing / scope movement. Harder to go from Breathing to On Target fast (at least not as fast and easy as the .50 or other snipers
* Barrett .50 Cal / M107A1 – Good for drag scoping, long range shooting, has small breaths and movement in scope. Due to 10 round magazine, if you get really close you can ’spray and pray’ a few no scope shots, although 1-2 quick scopes / half scopes (will be discussed later on) would be preferred. Downside is, it is a bit different of a quick scope compared to the Intervention, the thermal scope does not have Camo and looks awkward.
* WA2000 – This is a pretty decent 7 round rifle, which was used in Hitman games in the past. The rifle is quite accurate – much more resembling the .50 than the Intervention in breathing / motion while scoped in. The gun is most commonly seen with either a silencer or thermal, and out of all the snipers is most often to be seen paired with BLING as perk #1. I personally would recommend not using this rifle, due to hit reg happens quite often.
* M21 Enhanced Battle Rifle / EBR : This 10 round rifle has almost no recoil, is unlocked very late in the prestige. This rifle tends to be sprayed more than shot to be a One Shot One Kill. This gun gives a lot of hit reg, but is very very accurate for headshots and such. Again, I do NOT recommend this gun for CQC Sniping, and the .50 is as accurate, and has the same clip count.

I personally would recommend you do NOT use the WA2000 nor the M21 EBR. They cause a lot of hit reg, and they have issues getting hit reg with quick scopes consistently. I use the Intervention with a Thermal scope for closer range maps, or maps with poor lighting (Under pass mainly) or maps with a lot of grass for counter / other snipers to sniper from (Wasteland). I use the .50 however for long range maps with FMJ attachment.

STEP 3 : Setting Up Your Class
Now that you have picked your rifle, or you want to test two or more out… Lets make a class shall we?

I highly recommend starting with this set up.

Primary Weapon : Sniper of your choice with either Thermal, ACOG, or FMJ (I recommend thermal for beginners)
Secondary Weapon : I use the M93 Raffica with Silencer (so I can be stealthy when I need), it allows me to be silent, but have good fire power and range! I love this secondary!

Semtex or Frag (your pick, doesn’t matter being this is a cQc guide for sniping not ‘nading). NOTE : When you get better, or from the start – I’d recommend switching to Throwing knife (explanation below)
Stun x2 (so you can slow down fast movers which makes it easier to quick scope, and it also allows a wider hit reg area around its impact… Thus allowing you to have more of an idea where your target is.

Perk 1 : Sleight Of Hand Pro – Please make sure you have pro, will explain below
Perk 2 : Stopping Power – Does not have to be Pro, but is required !
Perk 3 : Steady Aim – This can be swapped out but for starters / new comers to quick scoping – I highly recommend using Steady Aim. Pro is not required.

Explanation for set up
Sleight of hand pro allows two things. 1 being you can reload very fast, which is VERY key when using the Intervention. 2 being it allows you to go from hip fire to looking through your scope MUCH MUCH faster.
Stopping power allows you to do more OSOK, and will help you tremendously with CQC with any weapon, especially a sniper.
Steady Aim : Steady aim makes your cross hairs (white ‘arrows’ on screen) smaller or closer to the center. Which allows for easier no scopes, and helps guide you to the center of your screen – Which helps with quick scoping. Steady Aim Pro allows a sniper to hold his breath longer for long range hard scopes, so its a double win for over all snipers.

Now earlier for your Equipment I mentioned a Throwing Knife. The reason I had mentioned it is because; When up close to an enemy – sometimes you really don’t have the time to quick scope, and no scoping is very inconsistent – Also you can get hit reg and that would royally screw you over when really close to a target with a sniper. Throwing knives do not get hit reg, ever. They are thrown just as if you were to quick scope, so it helps you in both ways. Also being you are not using scavenger – you wont resupply your equipment, but you CAN pick up the throwing knife over and over. Also, when climbing ladders to get vantage points – you can throw a knife while on ladder – in case someones waiting for you up top.

STEP 4 : Picking a Sensitivity For YOUR Shooting Style
If you use a high sensitivity (8 or higher) then you will want to pay close attention to my guides explanation of DRAG SHOOTING. If you use a low sensitivity, such as 5 and lower – then you will want to pay close attention to QUICK SCOPING and LEADING. Now, if you are a 6 or 7 user… Then you will want to pay attention to it all, mainly the QUICK SCOPING.
You cant drag shoot with low sensitivity – and it’s hard to quick scope with high sensitivity (until you get really used to it). That is why I am giving you an idea to which parts to pay close attention to, although I recommend you read it all…. Yes, even though its LONG !

Step 5 : The Different Types Of Shooting
Lets discuss the different type of shots you can perform, master, and own with in Modern Warfare 2 (there may be others but these are the basics).

First and foremost; Make sure you try to plant / stop moving BEFORE you pull the trigger. This significantly increases your shot accuracy – although it does make you an easier target – but hell! If you can kill them this way, does it matter ?
Drag Scoping / Shooting : Basically it is when you scope in to the left, or right (or top or bottom or a mixture of them) and move your scope in a fast movement OVER your target, and time your shot out so you basically PULL your bullet onto the target . . . This takes a great deal of timing, and good reflexes. It is the HARDEST shooting style, which is why many do not do it, or are bad at it / slow. A good way to also use drag shooting to vector / find your targets general area is to drag it over bushes, or the map – and if you see your scope movement pause for just a second – there might be someone there (console only I believe). Also, when dragging that pause can help in timing your shot if you have a keen enough sense of eyesight and reactions to notice it.

Leading : Basically, put the cross-hairs in front of a target, and let him walk into his own death trap. I personally hate leading unless close range. At long range, leading can be foiled too easily. They move left, right, stop, turn around, or you miss time it one time and you just waited – to look dumb. Although, it can be effectively used – if you get really used to doing it. Also, you’d need to get the timing down on when to hold breath and not. For up close and personal, this shooting style changes though, and I will explain why. With anything but 10 sensitivity level 2, you cant full on keep up with someone who books it around a corner within 10 feet of you. This is where leading comes in handy. You have to stay scoped out, then scope in right in front of them, and then fire fast – or lead it in front of them – scope in, follow/drag it into them. Although, if your lead ends up being behind them, drag it forward in front of them.

Straight Scoping/Shooting : Straight up is my nickname for this. It is the straight up quick scope way, so to speak. This is where you lead a target, but you scope in and fire. You don’t combine this with much dragging or any other type (well, leading). This is a prediction style, but very effective. This style includes a lot of missing before you become semi good to good at it, so don’t give up hope. Example of this would be; Targets running right at you within 5 meters. You put the center of screen on his torso, hold L1 until the scope is about to show and fire… .OR until the inside of scope flashes onto the screen – then fire immediately.

Half Scope/Quick Scope : This is where it gets confusing if you were a COD4 sniper, or have common sense. In COD4 a quick scope was INSIDE THE SCOPE for under a second. If your inside of scope never shows, its a half scope. In MW2, I get told (when shooting within .30 seconds of the scope being on screen) – that its a hard scope. Which is wrong! It is still a quick scope, but… Many people in MW2 consider the new half scopes as the true quick scopes. Why? When you are about to bring the sights fully to the screen, you can fire and it is fairly accurate (not as accurate as just letting the inside scope pop up). So I am not sure which to call this style – Half or Quick Scope. This is more of a sub category of Straight Scoping/Shooting… Because you do the same shot, just you hold L1 less, so you don’t see the inside of the scope at all. . . Which leaves for a very impressive shot, but its a lot harder – and if not timed perfectly scope will pop up, or shot will go flying in a random direction.

No Scoping : I don’t know the styles for this, so hopefully someone will make a tut for it, other than myself. I out do the no scopers with quick scopes ALL the time, quick scoping is the best / most effective and efficient way of sniping within cQc! Well, that or pulling out your secondary… But that’s no fun !

Step 6 : Practice, Practice, Practice – and some more Practice
This all takes a great deal of practice. It takes a while for your muscles and brain to remember the timings, and consistently pull them off. You will more than likely be TERRIBLE at first, which is OK. You got to put in some practice and work into becoming a good sniper in cQc.

Some practice / drills you can run would include ;
-Have someone run at you or even sit still to start, and just get the timing of Straight Shooting down, then do Drag shooting.
-Have someone run towards you – but at a sleight side angle. As you get better at leading / predicting where he’ll be and being able to quick scope him… INCREASE the side angle. Eventually, he’ll be running sideways to you!
-Get on High Rise and practice Straight Shooting at ranges, and at a downward angle (where you are above your target). This drastically changes your shots.
-Do the opposite, shoot someone who’s on top of the helicopter pad on High Rise.
-Practice 360s and 180s to REALLY get used to your sensitivity… Do a spin, and scope in before you get to your target while still spinning, and fire – try to stop on or near your target. This is very hard, and takes a few hundred misses but will significantly increase your accuracy and timing skills for quick scoping.
-Try some half/quick scopes, figure out the difference in seeing through the scope and not pulling it all the way up – and pick which you will mainly do.

Those are just some, the last good practice I can say is – 1v1 Quick Scope. Don’t hide, run around rust with a friend or a better sniper – and watch the kill cams of a better sniper… They will show you timing, and where to shoot.

Also, practice the throwing knife just so you can equip’ it. . . This is a really handy tool, although challenging. . . But hell, so is quick scoping !

Step 7 : The Last Step : Finding Positions and Routes
Learning routes for Search And Destroy sniping is key, but you must also find points in which you can hard scope from, or have good vantage point for quick scoping from . . . Running in the open all the time is not a good idea just due to how accurate some guns (ACR for instance) are. They will eat you up !

Give +rep if this helped