ive just discovered the camp and killed off the two gang memebers who were hostile. but what im wondering is why taking any ammunition they have in the camp, such as dynamite, is considered as stealing and i get bad karma for it?

eh karma doesn't work in this game in general.

For instance i went on a killing spree and killed everyone in camp maccaran and the strip. and still have epic high karma.

not sure what you mean.

I think the deal here is that the stuff doesn't belong to the guys you killed, but to the faction as a whole - so you can strip the bodies without getting bad karma, but the stuff in camp isn't "ownerless" just because you killed the faction members in the camp.

what i mean is don't worry too much about stealing from powder gangers.
or anyone tbh.