GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: crowpopper on November 13, 2012, 06:22:38 PM
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I have my B51 in .25 it is shooting well at 45 FPE but for 14 shots on a 2200 PSI fill
I would like to reg it at around 1900 PSI which is where the power peaks on this gun and fill the gun to 3000 PSI I think I could gain a significant amount of shots at a pretty flat curve doing so. Any input from the PCP experts here
I have been into PCP's for a number of years but All I ever did was go for power and no shot count. thanks guys
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Somewhere in here. http://www.gatewaytoairguns.org/GTA/index.php/topic,38195.0.html (http://www.gatewaytoairguns.org/GTA/index.php/topic,38195.0.html)
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Regulating a PCP at the peak of it's velocity string, on the surface, sound like a win-win situation.... Unfortunately, at the power level you are talking about, it is VERY unlikely to work as you hope.... Currently, your gun is drawing from an air reservoir of what, 180cc? (not sure for the BAM, that's a guess).... When you shoot, you only use a few cc's of HPA (maybe 5?), so the pressure drop in the valve DURING THE SHOT is quite small, maybe only 50 psi, depending on how easily the air can flow INTO the valve....
Now, put a regulator in the gun, right up aganst the valve (the typical location) or nearly so.... The volume of air downstream of the regulator, including the air in the valve might be, what. 10cc?.... Now when you make a 45 FPE shot (assuming you could), you use HALF the air in that space, and the pressure drops in half.... so your AVERAGE pressure during the shot, instead of being just under 1900 psi, is more like 1500.... See the problem?.... If you think the regulator can operate quickly enough to keep the pressure topped up, you are mistaken.... It won't even have started to open before the pellet has left the muzzle....
I love regulated PCPs.... If I was designing a gun to shoot 45 FPE, I would have a plenum between the regulator and the valve of 45cc.... That might be 1/4 of the volume (or more) of what your reservoir holds.... Now your reservoir is only 3/4 as big (or less).... and there goes the shot count.... Now it's not quite as bad as I've said here.... If you want to achieve the same FPE you get now at 1900 psi, you can regulate the gun at, say, 2000 psi and move the regulator far enough forward to provide, say, 1/2cc per FPE instead of the 1cc I strive for.... Going smaller than 1/2cc per FPE, however, will result in you either not getting the power you want.... or having to up the regulator setpoint so far that your shot count will suffer....
Bob
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Thanks for input bob!
I dont know the volume of the B51 I know the tube is a hair bigger than an Mrod. And you know the math more than I so I will prolly not screw with it LOL
I am actually looking into getting a 32 bbl and making this a round ball shooter since I can crank it up to over 60 FPE
or down to 35 FPE based on spring swaps.
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I looked up the volume of a B-51 reservoir, and it's 196 cc.... The MRod is 215....
Bob
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Those Andruis regs come with a reservoir spacer.
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hmm maybe the wall thick ness is different and the valve farther forward in the Bam?
I will measure OD of the air tube tomorrow I am prolly wrong plus the Bam could be shorter
Whats an Andruis Regs?
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Audrius Rusys in Lithuania (pcpregulator@gmail.com) . This guy makes regulators for sale for the B50 among others. Somewhere on utube is shown someone installing one of his in an Evanix Blizzard s10.