Weapon attachment gone bad

[SpaceRangerZ]

First of all : This was planed to be an craftable that sits AROUND another gun, like an added supresor etc. The model was placed correctly in Blender and works but not in the right way lol. I tried to use the supressor for the SMGReplacer as the base for it, duplicated it´s CK edits and changed some stuff here and there but after crafting the thing, the base weapon is invisible, he holds it like that, walks extremly slow and doesnt shoot in first person, where its invisible.

Anyone any idea or a guide for adding attachments?