I have had my rifle rebarreled and my T8 is now redundant. Its 5/8 by 18tpi however I am having my gunsmith check that offthe old barrel. 99% sure. It is well looked after 7 years old, been through the proof house and had a neoprene jacket. Sprayed with light oul after each use. works as well as it ever did. No dents/rot. First 75 ono. Needs to be face to face or via RFD at your expense, probably best face to face. I am near Glasgow Thanks Steven.