Hi Dan, I put a 20" long 9mm barrel on a disco sized tube, with a .228 transfer port, charged to 3000psi. with a 58 grain 9mm. pellet the max velocity was 980fps. One issue with a big bore with a big transfer port is to have the receiver attachment to the tube be strong enough so the receiver doesn't come loose from the upward force of the air. hth
Its more mad max than my mad max build .
Hi Dan, The gun had a poor shot count, because I had given the hammer twice as much travel as it needed, which caused a longer valve duration than needed which wasted air and the hammer spring was very long so it couldn't be very stiff because the valve duration was all ready to long, which caused the valve to be very bouncy, which wasted more air.
Hi Dan, I was getting 4 shots right at 900 fps. with the 58 grain pellets. If the gun had been built and tuned better, without the air losses I think it could have gotten 6 shots at that velocity. hth
I cut off heads and messed up the audio...
Quote from: BigBird on December 11, 2020, 12:24:09 PMI cut off heads and messed up the audio...Sounds like you're in a witness protection program but great stuff! It would have been cool to see the target.
Quote from: JPSAXNC on December 10, 2020, 06:51:05 PMHi Dan, The gun had a poor shot count, because I had given the hammer twice as much travel as it needed, which caused a longer valve duration than needed which wasted air and the hammer spring was very long so it couldn't be very stiff because the valve duration was all ready to long, which caused the valve to be very bouncy, which wasted more air. Sounds like a case for a shorter stiffer spring or adding a 50 caliber barrel! Quote from: JPSAXNC on December 11, 2020, 09:55:52 AMHi Dan, I was getting 4 shots right at 900 fps. with the 58 grain pellets. If the gun had been built and tuned better, without the air losses I think it could have gotten 6 shots at that velocity. hthNice. 6 is still an ok shot count for hunting. What liner and did you use stock parts?Here is a vid. I am not the best editor. I cut off heads and messed up the audio...