Author Topic: Travis's Bulldog power valve  (Read 424 times)

tkerrigan

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Travis's Bulldog power valve
« on: May 25, 2018, 07:27:52 PM »
Travis of jeffersonstateairrifles has had my Bulldog for about the last 9 months working on a improved air valve and boy did he succeed.  I'll get right to it.  These speeds are with the spring loose in the housing.  The spring is about half the strength of the stock so it is very easy to cock.  126gr .356 BBT did 895 at 2500psi, 915 at 2700psi, 928 at 2900psi, 943 at 3000psi, 961 at 3225psi, 973 at 3400psi, 989 at 3500psi, 999 at 3800psi, 1012 at 4000psi.  I don't recommend the higher pressures to  anybody, use them at your own risk.  I was searching for valve lock and didn't find any.  Using a 180gr spitzer it did 814fps -265fpe at 3000psi and 875fps-306fpe at 4000psi, that was yesterday.
Today I turned the hammer spring all the way up.  A 165gr did 879fps-283fpe at 3000psi,  948fps-329fpe at 4000psi.  A 173gr swaged did 811fps-253fpe at 3000psi, 901fps-312fpe at 4000psi.  And the 180gr from above did 908fps-330fpe at 4000psi.  Travis says that the power can be raised even more with a stronger spring.  I had already ported my gun before Travis got it and it was shooting 241fpe max.  All that is in a  thread "working on the bulldog" in this gate.
https://www.gatewaytoairguns.org/GTA/index.php?topic=107531.0
Regards, Tom


  • Jefferson, OR

Alan

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Re: Travis's Bulldog power valve
« Reply #1 on: May 26, 2018, 06:11:53 AM »
It appears you're happy with the FPS, but I'd be more interested in how well it groups, and with which projectile.
  • Roswell, New Mexico
Alan

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tkerrigan

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Re: Travis's Bulldog power valve
« Reply #2 on: May 26, 2018, 08:09:26 AM »
That's next, still have to do the lighter rounds.  Bulldogs are not known for tight groups, but maybe there will be an improvement due to bullets at higher speed.  Regards, Tom
  • Jefferson, OR

Christopher

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Re: Travis's Bulldog power valve
« Reply #3 on: May 26, 2018, 04:50:08 PM »
Nice numbers. Those SS valves are definitely a game changer....do you use a factory air tube at those pressures? Just curious....

Thanks,
Chris
  • dead end road KY

tkerrigan

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Re: Travis's Bulldog power valve
« Reply #4 on: May 26, 2018, 07:59:15 PM »
Factory air tubes will take a lot more than 4000psi, but I'm only doing it one set per bullet weight to check speeds and look for valve lock.  None yet.  Once I get through each of my bullet weights I won't be using it over 3000psi unless for demo purposes. 
Regards, Tom
  • Jefferson, OR