My .20 Avenger, my idea and Rick Smelko's metalworking magic handiwork. The gun still needs the tactical grip assembly by Anthony B. I apologize for not being able to remember his last name at the moment. The gun is extremely accurate.
The .22 stock magazines work perfectly. Most be due to the way Rick Smelko beveled the breech end of the barrel. I've used all my mags multiple times with no issues, the stock single shot tray works well too.
I'm going to use the gun for field target. Avg. fps is 798, avg.fpe is 19.2, reg is at 1200 psi, hammer spring is 1 turn in. At 32 yards I'm getting sub 1/2" groups. The barrel is more stable than the stock barrel, I see no poi changes from normal knocks and impacts. Shot count is about 50 with the 2 short air tubes. Refill at 30 shots during competitions to be safe. Needs more experimentation and fine tuning, but I'm very happy with the progress so far.