200FPE Disco Build .357

[rsterne]

If you are using a separate bottle, I would think it would make the most sense to use a regulator that simply threads into the bottle, like a Ninja.... You can purchase them in any pressure you want, up to 3000 psi, in 200 psi increment (1800, 2000, 2200 etc.).... Since you are using a Disco as your base, and you want a gun that shoots over 135 FPE, using the full Disco tube as your plenum makes sense, as it is 135 cc.... The very simplest way to do this it to simply tether the bottle to the fill fitting on the front of the main tube....

I would not recommend using an in-tube regulator when going for over 100 FPE, you simply won't get enough plenum, unless you mount it in the front of the tube.... and then you will have to anchor it against the end force created by the pressure differential across it....

Bob

[TroyHammer]

That make sense Rsterne. Thank you again for the knowledge. Weren't you able to get over 125fpe @ only 1500psi or so? I'll have to go back and check your double disco cothran valve thread.

[rsterne]

With the 78 gr. JSB pellets I got 111-113 FPE at 1500 psi.... I got 131 @ 1900 psi and 137 FPE @ 2000 psi.... That was with a 28" barrel....

Bob

[TroyHammer]

This might be the perfect setup for a regulated double setup.

[rsterne]

Just a quick off the cuff calculation would go like this.... If we assume 2000 psi and 135 FPE, with an efficiency of 1.35 FPE/CI, that needs 100 std. CI of air per shot.... The lower tube is 120 cc (7.3 CI) at 3000 psi, and the setpoint is 2000 psi, so we have 1000 psi (69 bar) of "headroom" which gives us 7.3 x 69 = 504 std. CI of air available.... That should give you about 5 shots before the lower reservoir pressure drops below 2000 psi.... If you tether the gun to a 3000 psi regulator you can shoot as long as your SCBA tank lasts, and untether whenever you want for 5 shots.... Sound very workable to me....

Bob