Believe it guys a few of us have undertaken this challenge and so far 3 have done it on a stock air tube! I have a .25 Synrod with 22" TJs barrel. Internals are Huma regulator with a hogged out hill gauge port and a hill valve with light valve spring. Lightweight hammer SSG and .162 TP. Got 40 shots at 853avg on regulation! After that got 8 more shots down to 830. Reg is set at 1950psi and filled to 3200psi for the test. There's a thread that might be worth checking out if anyone is interested
http://www.gatewaytoairguns.org/GTA/index.php?topic=116706.0
http://www.gatewaytoairguns.org/GTA/index.php?topic=116706.0