This might be a project in the spring... Question: How easy /difficult is it to replace the existing barrel with steel combo sleeve, to a new barrel ? Then, how 'secure' is the new barrel attachment to the action sleeve ? Reason I ask is Walther's blank barrels here: http://gunspares.co.uk/shopdisplayproducts.asp?id=24911&cat=.177+(4.5mm) at 605mm , is it advisable /ok to cut it down, to say 41cm (like Steyr length), and then have it machined for the Fwb fit, and carbon wrapped for stiffness ? Am wondering about the polygon one..