Sorry, I don’t know why it took me so long to notice your question, probably too late since it’s been like a year lol. I had completely forgotten about this post been well over 5 years in like 4.9 when I was still cutting my teeth haha.
The problem was simple, the mesh I was using was just an empty mesh it had no collision box. Nowadays I use a separate collision blueprint that’s invisible in-game and attached to the player’s hand, and only activated upon animation. I don’t actually have my weapon meshes do anything, they’re just there to look pretty.
If you wanted to prevent a mesh from clipping into another object, i would suggest starting off by adding its own collision box and blocking all dynamic