Is there an option to turn off owned weapons? The first one I did stealing Post Op delivery trucks was a total bore.
Yes there is if you read the hosting screen details. You need to set it to forced and pick ups, but there is a bug that needs explaining before you try it.
Ok, we've got two PS3s next to each other. I was testing a deathmatch I made and invited the girlfriend into it. I'd set the weapons to forced and pick ups already, but when she came in on her screen it said "owned and pick ups" . We played the deathmatch and as it turned out, the setting had changed to owned and pick ups. After a bit of experimentation we found that once she was in the room, if I started to toggle the weapons settings her PS3 started to mirror mine. So in the end we managed to get the setting right on both our screens and it worked in-game.
What you need to do, it seems then, is toggle the weapon settings just before you start the match and leave it on forced and pick ups and it should be ok. Hope that helps.
Edit: nope can't find those setting options in the new games so far, take that weapons setting advice for deathmatches.