is there anyway i can make it so it looks correct when you hold a weapon in thirdperson, so your arms aren't just holding up air?

Of course there is, how else would it have been done by the community for custom weapons if it was not possible?

I'll send this topic to Saje, he should be able to help when he has some spare time.

Third person animations are selected through the "Player anim type" attribute within a weapon file. There are only a couple of options to pick, not all weapons are gonna match up but you can select anim type by class. For example if I have a long weapon like a sniper rifle I can make sure it looks like he's holding it like a sniper rifle and not a pistol, also vise versa. If you get a weapon that doesn't match up even with it's class selected I would try others anyway but beyond that there isn't much you can do.

so after the player anim type there isnt really anything i can do? because ive tried changing that i havent tried all of them but ive tried a lotand they still havent worked

so after the player anim type there isnt really anything i can do? because ive tried changing that i havent tried all of them but ive tried a lotand they still havent worked

The animations are designed to fit most weapons but yeah in the end if they don't fit then there isn't much you can do other then trying to reposition tag_weapon on the third person model.