When inserting Warbound weapons, I have a odd glitch where if i crouch, crawl, or sprint my character will sometimes fold in on itself or body parts will be glitched inside myself. I use both the old and newer versions of Warbound guns and all will have the same glitch, to my understanding this only happens in this certain game.
Images: https://gyazo.com/1fdac7d220d0610f9e1d4dd0bc2c87e5
https://gyazo.com/b07536ea52290f951bf035fc635222b4
https://gyazo.com/52cb0dfcb6b192662a1b002dc83e1569
I don't know much about warbound weapon things but you can try to set can collide of weapons to false if the body parts are dynamic.