And another tip: there are only three “instantaneous effect” weapons: the pistol, the assault rifle and the shotgun. All others take time for the projectile to travel to the target (including the sniper rifle; though it does travel very quickly, you still have to lead a moving target). Of course, the shotgun and AR are useless at range.
The pistol is probably the best overall weapon in the game. It does good damage, can fire fairly rapidly, head shots kill, projectiles are instantaneous, and it has the scope. Just don’t smack anyone upside the head with it if you’re in a hurry - the recovery animation is too long. The best weapons in hand for smacking are the AR or the Plasma Pistol. With the PP, you punch (rather than actually hitting with the weapon) and it has a good recovery time so you can punch again quickly if you need to.
Needlers can be quite deadly, but typically only in open areas. In narrow areas or areas with a lot of cover, it’s too easy to dodge the needles. And if you can get seven needles into a target, they explode nicely, taking anyone around them out as well. One of the better weapons to use against Elites, in my experience. They don’t work at all against a defensive Jackal or a Hunter.
Also, Stinkpalm, in case you haven’t already noticed, plasma weapons cannot be reloaded. You have to ditch a used weapon for a new one. Plasma weapons work well against most Covenant, and have a stun effect. Just don’t lay on the trigger or they’ll overheat.
Another heads-up about Elites: their shields recharge just like yours. So if you are plinking at them with the AR, you will use up a lot of ammo with little effect. If you’re going to fight them, don’t play the “fire, duck behind cover, repeat” game (a game which they are very good at, by the way). In Normal difficulty, you can usually get away with just charging them with the AR, so long as there aren’t a lot of other Covenant in the area. Also try to sneak around behind them if they are hiding behind cover - they don’t have motion trackers, so if you are fast you can catch them flat-footed.