SRS99D-S2 AM sniper rifle

The Sniper Rifle System 99D-S2 Anti-Matériel (abbreviated SRS99D-S2 AM), more commonly known as the SRS99D-S2 AM Sniper Rifle or simply the Sniper Rifle is a ground firearm used by the UNSC.

Introduction
The SRS99D-S2 AM, a variant of the SRS99C-S2 AM Sniper Rifle seen in Halo: CE and the SRS99C-S2 AMB seen in Halo 2, is featured in Halo 3. It is an extremely powerful weapon and is relatively the same as the SRS99C but with some technical changes from the previous games.

Summary
It is a semi-automatic, gas-operated, magazine-fed, and long-ranged weapon. It is relatively the same as the SRS99C-S2 AM and AMB Sniper Rifle but with some design and technical changes. It still fires the 14.5x114mm APFSDS (Armor-Piercing Fin-Stabilized Discarding-Sabot) round semi-automatically from a four round magazine and has a 5x and 10x scope with real-time display, which is a variation from the scope mounted to the SRS99C-S2 AM, which had a 2x and 10x zoom, but now it shows everything with an infrared/topography view of what the scope sees. Its power as well as accuracy and range are essentially the same compared to the SRS99C. Its rate of fire has slightly dropped, however, being only about one round a second. This is speculated to prevent people from quick shot ambushes at close range. It also has more recoil; forcing the user to readjust the sights after every shot. Unlike the Battle Rifle if you shoot a player in the head it will kill them in one shot. This rifle will sometimes kill an opponent if you shot it in the chest or groin. You can also kill an opponent with a ricochet shot. The armor-piercing rounds can plow through most armored opponents and lower their shields enough for you or a teammate to finish them off.

Changes From The SRS99C Models

 * New muzzle brake with front iron sight
 * Foregrip, body, and stock has been altered
 * The scope now shows real-time with an LCD screen and infrared/topographic vision
 * It now has a trigger guard
 * The range & elevation indicator from Halo 1 has returned.
 * The SRS99D-S2 AM now has a new flat matte black color finish to it
 * Recoil affects aim
 * Does not have night vision
 * You do not have to lead a moving target as far as in Halo:CE and Halo 2, even at full zoom you only have to lead a running target by a centimeter or two.

Physical Description And Appearance
The SRS99D-S2 AM is a semi-automatic UNSC sniper rifle that fires 14.5mm x 114mm APFSDS (Armor-Piercing Fin-Stabilized Discarding Sabot) rounds from a 4 round magazine (a.k.a. the mag). It is designed in the conventional layout, so the mag and operating system are located in front of the trigger. The magazine does not fit flush.

This powerful weapon is gas-operated and therefore must be cocked to load the first round. Once the first round is fired, the gases from the previous round forces the bolt back and forth and continues to do so until the mag is empty. Once the mag is empty, the bolt (although not illustrated in-game) locks back and the mag is removed (although there doesn't seem to be a bolt catch or magazine release button on the weapon). After a new magazine is inserted, the bolt catch button must be pressed which launches the bolt forward chambering a new round. The bolt used to chamber the round is located on the left side of the weapon and moves during operation. It appears that there is no ejection port illustrated on the weapon, though empty shell casings can be seen ejecting from the right side of the weapon during gameplay.

The SRS99D is about 187.5cm long and is completely interchangeable. From the barrel to the breech to the stock, everything can be changed to fit the current situation and satisfy the operator. The SRS99D in Halo 3 has some notable changes from the SRS99C models. First off, it is fitted with a 5x and 10x scope that shows real time images in infrared/topography vision when not looking through it (the infrared/topography vision cannot be activated while looking through the scope). When looking through it, the scope shows a target's distance and elevation. The SRS99D also has an altered foregrip and stock as well as an altered body and sports a trigger guard. The barrel also now has an iron sight. This weapon does not posses a safety and has a frame that serves as a carrying handle as well as a scope protector and a folding bipod located in front of the magazine on the underside of the gun, though it is impossible to unfold and would not serve any purpose if it could unfold, as there is no notable unsteadiness or shaking while looking through the scope, and therefore no reason to utilize a "bipod".

The SRS99D-S2 AM Sniper Rifle offers an electronic scope which provides 5x or 10x magnification. While looking through the scope without engaging the electronic magnification, an infrared and topographic view of the surroundings is seen. However, while engaging the electronic scope, in the bottom left-hand side appears the phrases: DIST and ELEV indicating that the sniper rifle has the capability to measure such variables.

The SRS99D-S2 AM Sniper Rifle bears much resemblance to the Denel NTW-20, sharing many of the same features, including the stock, carrying handle/scope guard, the flash suppressor, and even the extremely large caliber.

Ammunition
The Sniper Rifle has one of the most advanced ammunition types in the game. Its rounds are large in both length and width, and are equipped with four symmetrical fins on the sides of the round, stabilizing its trajectory to results of amazing accuracy, with a hit ratio of 97.3%. While these fins provide increased accuracy, they also prevent a seal from forming between the bullet and barrel. A sabot is used to plug up this empty space, and is forcefully discarded from the bullet upon leaving the barrel.

The rounds themselves were inspired by the 14.5 × 114 mm Russian made projectile, used primarily in HMGs and Sniper Rifles. The rounds are described as being made of very hard metal, so they are probably made of a skin of hardened steel or titanium, with a hardened core of extremely dense tungsten or depleted uranium for maximum penetration. However, despite being labeled as Armor Piercing, the Sniper Bullet is actually Anti-Materiel, meaning that it is specifically designed to pierce body armor, energy shielding, and all types of flesh, but not heavy armor plating, like that of a tank. Therefore, the weapon is entirely useless against vehicles unless you have a clear head or body shot. The only reason for this is because of the Covenants' advanced armor. Modern day weapons and ammunition used against Covenant armor and shielding systems would seem ineffective, this is why most UNSC firearms use large types of ammunition because they are mostly use for their effectiveness in armor penetration. However, in both Halo: The Fall of Reach and Halo: First Strike, there are severally in-book references to standard UNSC personal and the Spartans using the SRS 99C-S2 even before humanity had learned of the Covenant's existence.

However, as an anti-material round, the penetration and stopping power is supremely effective. It has been demonstrated as having enough power (on Normal) to punch through the torsos of two Brutes (although it only knocks off their armor) and kill a Grunt standing behind them. The round possesses enough stopping power that a quick follow-up shot will kill both Brutes.

The large caliber rounds make it necessary to have a small magazine size and small combat loads (28 rounds total in Halo:CE, 60 rounds total in Halo PC,  24 rounds in Halo 2 and 3.) However, a "full combat load" was described in Halo: First Strike, and in the Halo:CE level Truth and Reconciliation you start with a Sniper Rifle that has a 68 round load, however, this is the SRS 99C-S2.

The Sniper Rifle's rounds leave behind a trail of smoke. This may be intended to act as an aiming aid for a sniper in a manner similar to a standard tracer bullet, or may be an unintentional result of the sabot's separation from the rest of the round. Another explanation could lie in the fact that the high speed of the round causes friction with the air, resulting in the round is heating up and smoking.

Tactics
For more in depth tactics on the SRS99D-S2 AM, look at HaloWiki
 * Because the Sniper Rifle is extremely powerful, but has a small combat load, it's not good practice to use this weapon against weaker enemies (Grunts, Drones). However, the SR's penetration capabilities and superb, long range accuracy make it excellent for killing higher ranking enemies at long range, which, in turn, disorganizes and demoralizes the enemy troops, making combat against a large ground force easier.
 * Also, without zooming, looking into the view screen one sees a completely green version of what they're seeing, but enemies, players, weapons, outline of terrain, etc. will appear white.
 * The Sniper Rifle shot can be used in close combat as a shield remover, followed by a melee which will kill your opponent, although this is hard, and often considered cheap.
 * If you don't feel like moving to a new position after you take a shot you should at least find a good piece of cover.
 * Camping at a safe location and dispatching targets at long range is the only "true" way to snipe.
 * Always aim your shots carefully with the sniper rifle. You should focus on someone's head and follow them around until you are sure you can kill them in one hit. Then you should move to a different spot to snipe.
 * A tactic performed by professional snipers today, is to move from location to location after each kill or round fired, never revealing your location.
 * If you do camp you should have one person guarding your back. More than one person guarding you can look like a big threat if an enemy spots all those people.
 * Another tactic is having 1 player with a sniper rifle and another with a close ranged weapon, the player with the close ranged weapon helps spot targets and defends the sniper from close range attacks.

Pros

 * Like the Beam Rifle a headshot is an instant kill unless the target has an Overshield or the rules of the game have been altered to shelter the player in any way, shape, or form.
 * It can also make four shots in rapid successions, which is impossible with the Beam Rifle. (which is subjected to overheat easily)
 * You do not have to aim higher than your target, due to the fact that the rifle's shots are not affected by gravity, unlike Sniper Rifles used in the modern world today.
 * "No-Scoping," a tactic which involves firing the Sniper Rifle without using its scope, allows this weapon to be used in close-quarters situations. However, this tactic takes a little skill and a little luck. It is recommended that you take out targets with your scope at long range before they move in close to you. If they do move in close, keep a secondary close range weapon like an Assault Rifle.
 * Unlike most Covenant weaponry, including the Beam Rifle, you are able to pick up ammo, so you don't have to discard your weapon when running out of ammo.

Cons

 * A sniper usually needs to find a safe location for him/her to snipe, since if you are spotted by your opponent, they will attempt to get close and kill the sniper with an Assault Rifle, Needler, or a Shotgun
 * The Sniper Rifle is definitely useless in close range combat, unless you can perform no-scope kills as mentioned above, although in Matchmaking, this is prone to happen in sniper-only games.
 * Due to larger recoil than it's predecessor, using the Sniper as a "Shotgun", is much harder than it was in Halo 2 and Halo: Combat Evolved. If the user is too far away, firing while not scoped-in, even when you are aiming at the head it can easily miss. Also, because there are only 4 rounds per magazine, a player with the sniper rifle has to reload frequently.
 * Low overall ammo. It is very hard to find any available ammunition on any map (for the exception for a shotty snipers match).
 * Due to the smokey trail, cover is blown the moment you fire, and as result, enemies will attempt to snipe you back.
 * After firing, the recoil will cause the weapon to raise up, and you will have to reset your aim.

Possible Manufacturer Change
In Halo 1 and 2 a cyan logo identical to the "trinity" emblem can be found on the stock of the Sniper Rifle System 99C-S2 AM. However, in Halo 3, the emblem is absent from the SRS99D. In part 1 of the Arms Race video trilogy, the SRS99D can be seen being made at Misriah armory on Mars. However, the "Trinity" logo is seen on the rifle in the Halo 3 game booklet as well as in the Arms Race Part 1, where it is found on the stock of the "second" rifle in the magazine, and in part 3, it is visible on the stock of the rifle T. Rymarr uses to kill the Brutes.

Anti-Flood Tactics
In campaign mode, the Sniper Rifle is surprisingly one of the least effective weapons against the Flood. Due to the fact that the organs of the host are regarded useless and its insides have been converted into a liquid, it is virtually impossible to get a one shot kill against any flood target. It is possible that the upper chest of the Flood is vulnerable to the sniper rifle as that is where the infection form is lodged. It is better to use the SMG or Battle Rifle when combating the Flood. It should be noted that the rifle is capable of knocking off the Floods' limbs, reducing the threat level of a Flood form wielding a dangerous armament. This method is effective against the Flood Ranged Form.

Character Compatibility

 * Elites
 * Spartans
 * Marines

Trivia

 * The weapon, along with its predecessor, possess large rectangular Barret M107 style buttstocks, implying that perhaps Bungie had intended for the SRS99C and D to be bullpup fed, before switching to the reload animations seen in game.
 * The gun strangely ejects 7.62x51mm cartridges, the same as the MA5C's, despite the two guns having different calibers.
 * In the Halo 3 guide, on Pg. 163, it shows a picture of a Plasma Rifle on the line showing the respawn rate of the SRS99D.
 * The bullet will travel from the barrel to the target almost instantly, unlike modern day long-range rifles, where the bullet may take 2-4 seconds to travel over a mile. (Recent studies have shown that the newer Barrett M-107 .50 cal sniper rifle can travel almost this speed being 4 times the speed of sound.) now confirmed by Bungie, the bullet will only travel to the target instantly under a certain distance, over that distance, it may take 2 or 3 frames to reach its target, although unnoticeable during gameplay, it can still decide between instant kill(headshot), and a miss.
 * In Multiplayer most people will not move after they have taken a shot or killed someone with the Sniper Rifle, which can give away your position.
 * The SRS99D is powerful enough to take out a Wraith. All you have to do is shoot the Power Core in the back. *Although this event is exceedingly rare, it is possible for this rifle to deliver a fatal headshot to its user if fired on a very specifically angled surface as the bullet does ricochet at full velocity.
 * Seeing as the bullets of the Sniper Rifle can penetrate through opponents, it makes it possible to get multiple headshots and/or kills with one bullet. Although this is nearly impossiable to do unless in Custom Games or in Campaign.
 * If a player presses in the right stick to zoom in to the 10X mode then holds it in after the second zoom then slowly releases it, the zoom mode will return to its 5X zoom instead of completely disabling the zoom mode.
 * Some believe that the ammunition the sniper rifle uses is the extremely powerful .75 cal anti-materiel sniper rounds which are used (sparingly) by the U.S and British army. However, due to it being very expensive to produce and manufacture ammo it is seldom seen.
 * Unlike the sniper rifle of Halo CE, this sniper rifle lacks a night vision function in game. This may be because of the differences in weapon or the fact that it is unnecessary, as no Halo 3 campaign levels take place at night. Or because the Halo novels mention about Spartans having increased night vision sight so they most likely won't need it.
 * The rifle fires a .57 caliber round (14.5 mm)
 * When you deploy equipment while wielding the Sniper Rifle, the front rest and the bar over the scope go into the Sniper Rifle and come back out.
 * The SRS99D was used by T.B. Williams to kill a Brute Chieftain who had been responsible for the deaths of 23 Marines.
 * The sniper rifle was featured in the Landfall short.
 * Technically, this Sniper Rifle is scientifically impossible because its round flies straight and true, regardless of gravitational pull, humidity, temperature, wind speed, wind direction, and the Coriolis effect. This is most likely to keep the gameplay simplified.
 * The Max range of the scope's range-finder is approx. 275m. The max distance the reticule will turn red on enemies is approx. 142m.
 * A player once fired a round that bounced off two walls then went through his head. This is one of the most famous events to happen in Halo Multiplayer.
 * Due to lag(When the connection slows down so it causes jerking and delay in actions and animations), some players have reported being shot through solid walls.
 * In Halo 3, the recoil leaves the aiming reticule slightly above the area of the previous shot.
 * Bungie has stated that the Sniper rifle was not meant for no-scoping, and wishes they would have changed it in order for it to be almost impossible to no-scope like in CoD4, but decided not to because they didn't want to use another game's Mechanics.

Related Links

 * SRS99C-S2 AM
 * SRS99C-S2 AMB
 * Beam Rifle
 * Type-50 Sniper Rifle System