FX Feet are wet once more with a Fx Dreamline Tac-Compact build & mod

[Motorhead]

After some Chony time trying differing tunes for 8.4's, settled on Reg at @ 100/105 bar, power wheel on 8 where we have 900 fps. Down on PW 1 about 880 and maxed out @ 915.
As such we're back off the bell curve just a tad. It's quite and decent shot count too.

We got into hammer/spring area prior to final tune REMOVING the steel guide/weight & replacing it with one made from acetal. Lighter hammer = snappier shot cycle.

 

[$p00kygH0ST]

After some Chony time trying differing tunes for 8.4's, settled on Reg at @ 100/105 bar, power wheel on 8 where we have 900 fps. Down on PW 1 about 880 and maxed out @ 915.
As such we're back off the bell curve just a tad. It's quite and decent shot count too.

We got into hammer/spring area prior to final tune REMOVING the steel guide/weight & replacing it with one made from acetal. Lighter hammer = snappier shot cycle.

In matters of PCP tuning I'm a neophyte.

Wouldnt simply raising the pressure on the reg, going to the lower end of the appropriate hammer spring tension curve with power wheel setting where the strike is sufficient to get the same velocity with a shorter dwell give the same effect?

I'm asking In earnest.
I have, I think ,figured out my dreamline and crown pretty well as far as tuning goes. In every case producing 900fps in the 120-135 range has produced higher shot count than tuning at 100-105 BAR at the same velocity. Almost about 35-40% higher count at 125 (25.4-26.5gr) and 135 (28-33gr)

 

[Vetmx]

In matters of PCP tuning I'm a neophyte.

Wouldnt simply raising the pressure on the reg, going to the lower end of the appropriate hammer spring tension curve with power wheel setting where the strike is sufficient to get the same velocity with a shorter dwell give the same effect?

I'm asking In earnest.
I have, I think ,figured out my dreamline and crown pretty well as far as tuning goes. In every case producing 900fps in the 120-135 range has produced higher shot count than tuning at 100-105 BAR at the same velocity. Almost about 35-40% higher count at 125 (25.4-26.5gr) and 135 (28-33gr)

When you compare your starting velocities at 250b and your ending velocities right above your regs set point, then you’ll have the answers. If you are using too much hammer at 100-105b, it will show. If you aren’t using enough hammer at 120-135b, it will show also. My guess is you have the hammer set too high and too close to the plateau at 100-105 and you have an air hog.

Motorhead changed the weight of his hammer so now his gun is taking nice sips of air at a lower reg pressure and he can set his gun on the knee also and still get the velocity he wants with his caliber and projectile weight.

 

[Motorhead]

Yes the lightening ( removal of steel guide/weight ) has the valve NOT ABLE to be opened effectively at the higher pressure it was able to shoot stock.

 

[Motorhead]

Conclusion as to the WHY I've sold off all my previous FX's !! ... POI shift every damn time you seem to handle the AG or fiddle with it

Ok enough of these Soda Straw barrels !!! Gutted the entirety of barrel machining up a take off 17" cut to 14" ( 355mm ) .177 barrel from a LG110 STEYR to fit down within the brass dual port barrel thimble. All done the slip fit a sizzle fit only requiring a few drops of loctite 545 to bond & seal to the OEM brass thimble & threaded shroud mount to effectively secure it.
All the previous shroud mods adjusted to accommodate the added length from the OEM 300 mm to 355 mm barrel.

Over on the chrony the previous 900 fps was now 965 fps requiring the PW to be set on 3. Muzzle report fell further as efficiency gains utilized via a tad more barrel length.

On Paper .. HOLE IN HOLE at the 34Y zero range, Set rifle out in sun for a hour or so @ 117* metal/ optics temp ... very close & acceptable POI .. Bring into shop and cool off, knock it around mildly, take off scope & reattach and then re-shoot with same POi

Now I'm likely 1/2 pound heavier, but consistent and unchanging accuracy rules the day !!! Thinking we're finding improvement there !