I read about thuis gun a year or or so ago. There was a moderan version of it build and the two men who built it said that they could never figure out how they were able to produce these that many years ago. The most amazing part was how they were able to make the storage tank to hold the amazing 800 PSI.
I don't have the web site at hand, but there is a youtube vidio ashowing the build. You should be able to google it and find it. Very interesting too be sure.
1999 NEWMAR American Star (for sale)* Newmar Kountry Kklub # 19708 * THOUSAND TRAILS * 2006 Chevy 3500 Dually Dmax/Ally SOLD* Curt Q20 * Prodigy P2 *US ARMY 1965-1967 * Vietnam Veteran 1966-1967 * Life Member VFW *