34gr king mk2, velocity vs presure

[Avidrob]

FX IMPACT OWNERS.



what velocity are you getting with 34gr king mk2s?

And whats your setup (ie Barrel length, reg pressure, HST, VS.

 

[Hatmike]

I have 700 mm barrel .reg 145 to 150. Hammer spring is maxed. But turn power wheel to 3 or 4 they like to go about 850 for me

 

[stoti]

To start, I had the gun's settings on max or opened all the way, I had it shooting between 940-945 on average, with a max of 950fps. I then used the valve adjuster to lower velocity a little at a time until my accuracy was it's best and my ES the lowest. That turned out to be at 920fps. Impact MkII, 700mm barrel, regulator set at 150BAR, hammer spring pre load adjusted until wheel won't turn and then loosened a 1/4 turn, hammer spring adjuster wheel on max and valve adjustment knob on 3 1/2 lines or 8.11mm. The accuracy testing was done at 40yds, 5 shot group about 3/8" or so. Good luck!

Stoti

 

[Avidrob]

To start, I had the gun's settings on max or opened all the way, I had it shooting between 940-945 on average, with a max of 950fps. I then used the valve adjuster to lower velocity a little at a time until my accuracy was it's best and my ES the lowest. That turned out to be at 920fps. Impact MkII, 700mm barrel, regulator set at 150BAR, hammer spring pre load adjusted until wheel won't turn and then loosened a 1/4 turn, hammer spring adjuster wheel on max and valve adjustment knob on 3 1/2 lines or 8.11mm. The accuracy testing was done at 40yds, 5 shot group about 3/8" or so. Good luck!

Stoti

950fps !!! Is that with 34gr or 25gr kings

 

[stoti]

34gr. MKII's. No internal modifications to the gun. Mine is the MKII with the larger plenum higher velocities.

I just set the pre-load on the hammer spring adjuster tight and then back it off a touch. The first time I tightened it, I just made it kind of snug. My velocities were around 890fps. I went back and did it again until the adjustment wheel wouldn't move at all and then backed it off just enough so the wheel would function. Those few extra turns made a huge difference in the velocities. I think most people don't tighten the pre load as far as it will really go. I only got 950fps a few times, the average was 940-945 and the accuracy wasn't great. That's why I did the final tuning with the valve adjustment knob, to drop the velocity just a hair, improve accuracy and tighten up the ES.

Stoti

 

[Killshot714]

Did u start with the reg. pressure...Then hammer spring..then valve adjusts.. chronoing through out 

 

[Bob_O]

That is some serious power Kevin!

 

[Spray1Mark]

I also get 940-ish with the 33g in the MKII 700mm barrel and maxxed out, but haven't tried it on paper yet.

The 30 cal 50g gets to 940 as well for 98.5 FPE with the same settings, only problem is the damn probe screw backing out!

 

[ImpactX]

I also get 940-ish with the 33g in the MKII 700mm barrel and maxxed out, but haven't tried it on paper yet.

The 30 cal 50g gets to 940 as well for 98.5 FPE with the same settings, only problem is the damn probe screw backing out!

Be careful not to over power the impacts. The probe isn't able to handle so much power. I read somewhere, this guy shot his impact and the probe flew back into his shoulder. Ouch. The impact use a small set screw to hold the probe in place. Too much pressure will blow that set screw and the probe right into you.

 

[Spray1Mark]

I am going to loctite it for now and probably have another block made with a different screw type.