A year or so ago I bought a tester for the Vulcan. Might have played with it twice and that was that. $90 shipped conus and if you don't think it's worth it when you get it I will take it back and refund your money no questions asked. I should have said it's for a .22 Vulcan Bullpup. MORE INFORMATION. Having gone back and doing some research I believe I bought this regulator from Precision Air Guns and I also think Ernest was just switching over to working for them or something like that. At any rate this is the link to the regulator Ernest Rowe is using to adjust regulator.
https://www.youtube.com/watch?v=2TO6XkmRQOA&t=310s
https://www.youtube.com/watch?v=2TO6XkmRQOA&t=310s