SRS99-S5 AM sniper rifle/Gameplay

Campaign and Spartan Ops

 * The Sniper Rifle's usage against the Covenant and Prometheans in Halo 4 differs very little from its utilization in previous games. It is still the best weapon to take out enemies from far beyond retaliation range. Its power, however, has been significantly reduced. Even on Normal difficulty, a low-ranking Elite will survive a headshot from the weapon, unlike previous titles where one would instantly kill it straight through the shield. On Legendary, it can take an entire magazine.
 * Don't waste sniper ammo on small targets (with, perhaps, the obvious exception of Jackal and Crawler Snipers). The Sniper in Halo 4 only has a reserve of 16 rounds of ammunition, meaning you will run dry very quickly against the hordes of foes you face with it. Save your shots for Elites and Knights, using other precision or even automatic weaponry to eliminate the lower foes.
 * Relatedly, don't get too attached to your rifle. Unlike other games where upon you could carry a Sniper throughout the entire level, you will have to discard it eventually. With the low ammunition count, and the infrequency of the weapon's appearances, you will most likely run out of ammunition quickly, and reloads are unlikely to be found. Thankfully, the Rifle usually appears on levels where you can find the Covenant and Promethean equivalents (Beam and Binary Rifles respectively), so finding a replacement weapon to reach out and touch someone is not a supreme difficulty.
 * If at all possible, reload when there is only one round left in the magazine. The empty reload for the rifle is a lenghty one, and while the sound of the Chief loading a new round into the chamber with a metallic rasp worthy of a blast door opening, its not the best thing to be forced to do when under fire from multiple enemies. Pace your shots, fire three, reload.

Multiplayer

 * Once more, the Sniper Rifle's usage against multiplayer opponents has changed very little; it is still the go-to weapon to stop people halfway across the map (or further on the larger ones) from getting in your face.
 * The majority of the tips from Campaign apply to multiplayer, most especially the one regarding ammo. Normally a sniper rifle spawns with two extra magazines (8 rounds in reserve plus the four in the rifle itself), which, as any experienced sniper will tell you, go by incredibly fast. As soon as you run out of shots, grab any other weapon. Even a plasma pistol is more effective against an opponent than an empty sniper rifle
 * Keep a low profile; human opponents are much more observant than AIs, meaning that if they see you (even from halfway across the map) they WILL engage you. Take cover and pick off targets of oppertunity.

Multiplayer

 * In Warzone, the SRS99-S5 AM is a powerful tool. With the long sight lines on each Warzone map, a properly-placed sniper can obtain some impressive kill streaks and help their team immensely. The three variants of the weapon (End of the Line, which has reduced recoil at the cost of slightly lower damage, Arrow of Time, which has two extra rounds and no descope with higher recoil, and the Mythic Nornfang, which comes with a built-in damage boost and high-explosive ammunition that is capable of one-shotting any Spartan anywhere on the body as long as they don't have an Overshield or Enhanced Shield armor mod), increase its lethality even farther. While it may be tempting to do so, it is inadvisable to use it against bosses; their health pools are simply too large for it to be worth it. Instead, focus on the enemies attempting to take out the boss; a sniper with a good eye and a full weapon can turn the tide of a Legendary fight in their teams favor.
 * The Sniper is a power weapon on several maps, and controlling it is an essential part of any winning strategy. On many of the larger, more open maps (Viking and Basin for example), a good Sniper can decimate entire enemy teams and shut down objective runs with ease.