FX Barrel length vs regulator pressure & hammer tension

[DrSeagram]

I have purchased the new FX Hunter Compact in .30, my dilemma is trying to find the idea balance for the gun, with its 395mm barrel. My goal is to shoot JSB Exacts 44.75 grain at around 880fps, whilst not causing turbulence to destabilize the pellet & waste air. Which way is best to achieve this speed? Would it be with a higher reg pressure & lower hammer tension, or low reg & high hammer? This is made easier in the Impact as you can use the front valve adjuster to balance the gun, but obviously not on the Panthera?

 

[Emu]

There are two forces in fight: The one of the air in the bottle and reduced by the regulator that close the valve and the one of the spring of the hammer to hit the valve and open it for a fraction of second.

After a such preassure on the regulator the higher preassure will not allow the hammer to open adecuatelly the valve.

Set the hammer at middle tension, set the regulator at around 150 bar and measure fps. Later on go a little bit up and measure again. If it decrease fps, reduce bar on the regulator. Once you are close to what you are looking in fps, then go up or down with the hammer tension.

That is the must effective way to find the equilibrium on each rifle.

For example, I found that my Vulcan 3 700 mm .30 Cal. (that has not a second manometer, so getting to know the preassure on regulator is more difficult and require an different technic) is 140 bar to achieve 130 fpe.

 

[DrSeagram]

There are two forces in fight: The one of the air in the bottle and reduced by the regulator that close the valve and the one of the spring of the hammer to hit the valve and open it for a fraction of second.

After a such preassure on the regulator the higher preassure will not allow the hammer to open adecuatelly the valve.

Set the hammer at middle tension, set the regulator at around 150 bar and measure fps. Later on go a little bit up and measure again. If it decrease fps, reduce bar on the regulator. Once you are close to what you are looking in fps, then go up or down with the hammer tension.

That is the must effective way to find the equilibrium on each rifle.

For example, I found that my Vulcan 3 700 mm .30 Cal. (that has not a second manometer, so getting to know the preassure on regulator is more difficult and require an different technic) is 140 bar to achieve 130 fpe.

Appreciate the reply, but im more interested in the settings that work best with the shorter barrel length, to help increase stability, etc.

 

[seangabrell]

Are they unstable at your current tune?

 

[mackeral5]

I do not know the Panthera, but 75fpe in .30 cal and sub 16" barrel= fairly high final reg setting regardless of platform. I will be interested to learn where you end up in pursuit of your goal.

 

[PumaCarl]

My guess is 165bar for the reg. Regardless of platform, you want a short burp of hpa so that your valve is closed before the pellet leaves the barrel, or you will be wasting air and it will be loud. Let us know where you end up, I'm curious how the FX handles the short barrel compared to the short AAA Evol.

 

[Kenjeepman]

Most i could go on my 22 is 880 with 21.5 gr pellets 37 fpe (FX claims 40 max with a 21 slug) ithats with the reg at 150 hs 2,75. Didnt know if these regs can go higher than that.

 

[Trucker3573]

I don’t know about that particular platform but in my opinion there is only one way to set up any gun if you really want consistency and that is an exact balance between reg pressure and hammer tension. It’s all trial and error. You need to find the reg pressure that produces the velocity you want near the maximum capability of that part reg pressure. I know some run a higher reg pressure to open the valve less making a quicker shot cycle but when I’ve tried it velocities just aren’t that consistent.