Gears of War Xbox Live question

Got this awesome game for christmas and was stuck playing single player mostly. I finally decided to take it online after getting fairly far in campaign.

Okay, so I start off with that shotgun, that rifle, a smoke grenade and a pistol. Keep in mind I've only tried it a few times (maybe for 1 hour tops total), and I was told that you have to go FIND the other weapons like frags and the rocket launcher thing. But my question is this, WHY THE FUCK CANT I KILL ANYONE WITH THE RIFLE OR SHOTGUN!? Melee works great, if I sneak up and melee they WILL die, but I could unload an entire clip from the rifle in to my enemy and the MOTHERFUCKER SHOOTS ME ONCE AND I FUCKIN DIE!!! WTF!? I have not ONCE kills someone by SHOOTING them with either gun you start with.

What the FUCk am i doing wrong? Do I need to dump shells in to JUST the head? Of course that will probably be more common once i get better at playing overall while online, but is it that simple? WTF am I doing wrong? I don't even know where the other guns are and the enemy starts less than 100 yards away (it seems like) so its not like I even got time to go look for them before some fucker chucks a RPG at my ass from across the map.

Go ahead and talk shit and make fun of me, it's practically written in the rules that you need to talk as much shit about or to me as you can.

So I guess I just suck huh? =(

Damn, but im so good at Rainbow Six Vegas!

You pulling the trigger to aim. SHot gun shots are "tighter" and you can actually aim for the head and kill people faster with the automatic gun.

use the handgun for melee.

The only weapons that are available in online play, are all of them, certain maps have certain weapons and certain games have certain rules

You have to really unload with the normal machine gun. If the guy runs away the damage incurred will dissipate.

I saw guys fighting with the sniper rifle cause of the massive damage. It sucks when you get in close though.

I like the machine gun for far and the shotgun for close. I would like to find the bow weapon but I haven't gotten it yet...I keep getting killed when trying to pick it up.

It's tricky. You'll feel like you're just unloading ammo into opponents and they won't be phased by it.

The Lancer (machine gun) is a medium-distance weapon. You can put guys down with it, but it works best to help provide cover fire and flush guys out. The shotgun is a short-distance weapon, and works well because you don't need to aim it. That enables you to move and turn quicker, making you a more difficult target to hit. Won't make a dent at medium-to-long distance, though.

If someone has a shotgun out, roll back a couple of times and pull your Lancer. If they've got the Lancer out, close the distance and use your shotgun.

The cheapest move in the entire game is equipping frag grenades and using the melee attack to attach a grenade to an opponent. You can rack up kills that way, but everyone will hate you.

The boomshot (grenade launcher) kind of sucks because you have to be completely precise with it to make an impact. The sniper rifle is awesome at long distances but leaves you vulnerable to other snipers. It's a surprisingly powerful melee weapon, though.

It's tricky to get the hang of everything and you'll SUCK for quite a while. Soon things will feel easier and you'll notice more kills. Good luck man.