how do you get unlimited ammo for the guns?

The gun you have you got from another player who hacked it. The hacked weapons are really frowned upon by other players, who tend not to like it when you appear in a co-op session and fire all-day-long without needing to reload. Takes all of the fun out of the game. Just saying.

The gun you get from multiplayer in xbox live mode can be hacked or glitched out. If your gun has unlimited ammo it will show you the ammo or have no ammo at all. If you don't have any ammo but it still fires you have a glitched weapon. And having not to reload your weapons does tend to make other players mad and report you so I recommend that you stay to legit weapons.

It must have been a hacked gun because it had that much ammo therefore you can't get it in normal game you have to use a save editor

Hackers they are gust taking the fun out of shooting zombies and then going and finding more ammo that is the way it's meant to be played not to be hacked by hackers
By BIOSHOCK

hackers I was playing with one last night on the 6/5/2015 and he had the m16 hacked and he was taking all the kills and then when I reported him he kicked me.

hackers they are always making it better for them not others an I right.
Also where is the semi-auto ar and I can't find the dam thing if anyone knows where it is tell me so I can get it I have so many auto-rifles that players are giving me metal and other very rare equipment just so they can get a auto-rifle like wtf thats all people care about guns in this game I much better with a military machete with hot rod mode on it thats a killer.

I don't think is really ruining the game I myself actually hacked (I call it modding) a gun and it just made it more easy so I don't think it is bad at all it's not affecting y'all at all half the time the will duplicate the gun for you and if you don't like it kick them it's that easy guys

Ive played for one day and some guy threww out infinte torch axes then when he stopped he gave me guns that had infinite ammo with an m72 bolt rifle harpoon semi rifle m60 pistol explosive rifle and a stun gun that shocked torched and venomed a zombie and he didnt give this to me but he was walking around with a mounted turret with the mounts still on it jjust shooting it

I see nothing wrong with modding something for yourself, but leaving it for other gamers who don't ask for it - well, that's a bit rude in my opinion. You never know if you are going to come across some uptight person who is only into "pure experience" gaming and doesn't want anything modded. Power to them - if they don't want the mod, then it shouldn't be shoved in their face. However, the road goes two ways - they should stop dissing those who mod. We are just gunning for our own unique experience (no pun intended). Use a save editor to mod.

anyone also help me with unlimited ammo on Dead Island Riptide for xbox 360.
Gamer tag is kountrygrl2394