From Halopedia, the Halo wiki
- Smart scoping with the Needler is not as effective as it might seem; while it does increase the range at which the needles track their target, their flight speed remains unchanged. If engaging a target who is aware of you, fire from the hip for best results.
- If you end up on the wrong end of a Needler, a quick thrust around a piece of cover can save your life. Follow up with a grenade to deter the Needler user from following you for a clean getaway.
- Warzone and Arena feature two additional variants of the Needler, each being situational but efficient upgrades:
- Hailstorm: basically a straight upgrade to the standard Needler with a 50% larger magazine, faster needles, and slightly stronger tracking.
- Talon of the Lost: an anti-vehicle/anti-armor Needler. While not as efficient against something heavy like a Scorpion or Phaeton, it works well enough against Ghosts and Mongooses, as well as armored enemies or even bosses like Hunters, Promethean Knights, Pnap-pattern Goblins, and the Warden Eternal. It also appears in the seventh campaign mission Reunion.
- No matter the version of Needler you use, don't spare the ammo; if you think you have enough rounds in the target to kill them with a supercombine, hit them with a few more.