My Perrin turbo inlet pipe and the pipes of everyone else I know don't really fit the turbo well. It goes on, it doesn't go anywhere, it won't fall off, but the damn thing just doesn't seat perfectly. Maybe your jig needs adjusting.
You can make it fit if you loosen the turbo and readjust the turbo, but that can be a risky operation if you don't want leaks.
An e-mail I sent to you folks half a year ago recieved a response like "cut the pipe and make it fit". That isn't the type of response I expected.