So, I've been having this issue with FNV where whenever i or an NPC walks, a certain gun type will slant upwards. Anti Material Rifles, single shotgun, and rifles like the cowboy repeater slant, but using the Assualt stance by captain rex makes other rifles okay.

Opps thought it uploaded a picture as well,

Here is what I was talking about https://imgur.com/XEC3nuj

Are you using any animation mods? Post your mod order?

I'm only using hitmans and Shinyhax animation wise. But some weapon mod added some of WAR's third person stances