[Eeyore]

I bought a KA receiver and it came with a metal one piece hop up. I purchased a 6.03 Prometheus tightbore as well. Now part of the hop up is the little brass washer that goes over the inner barrel and sits just inside the hop up, well the inner barrel is too large for this ring. Is this a big concern? Do I need to find a larger one or can I just omit this small part?