Yes, I've sketched it as 3 pieces: inner barrel, outer barrel and ring.
Honestly, depending on how many you are making and your timeframe, welding may well be a good and cost-effective solution. It shouldn't require any special tooling on the part of the machinists unless you wish to skim the...
Just wondering why something like this couldn't be done? I'm assuming your piston is moving in the annular space between the barrel sections.http://files.engineering.com/getfile.aspx?folder=8ab91570-05f8-4776-9e69-1dc5d23cf4b5&file=sweet_jesus.JPG
