FX IMPACT MKII UPGRADE TO POWER PLENUM AND TUNED TO SHOOTING SLUGS

[SONG55]

 

I brought my Impact MKII 30 cal with 700 mm in October of last year from Palm Beach Air Guns. The gun didn’t come with power plenum then, but I was able to get one install and tuned to shoot slugs and pellets. The gun now have all new internal mechanical accept hammer spring along with bigger plenum. I was able to shoot JSB 44.75 gr. over 1000 fps with the help of my friend Chuck P. I have my regulator pressure set at 150 bar and power adjuster knob on line number 3.5 with the slugs liner, I tuned my gun to shoot JSB pellets and Varmint Knockers both 48 &50 grs. slugs around 935 fps. and getting very good shots count per filled. Here is the link to YouTube shooting 50 gr slugs. 







https://youtu.be/Ze5iX84ykAk

 

[spyde82]

Did you do anything to the VA spring or hammerspring??

i just installed the power plenum in my mk2 .22 but can’t get it to shoot 25gr over 970fps, and if i turn the reg pressure up the velorcity Gores Down 

hammer maxed out, reg at 130bars, and the VA all the Way out

 

[SONG55]

Yes, I use original hammer spring, it’s little longer and hit the vale much harder. Its will open up that valve upto 165 bar and shoot 48 gr slugs over 1000 fps. If you look at the picture above you can see the difference length between PP Valve spring and original MKII valve spring. I also cut off about 3 line of vale adjustment spring located between the bottle and the barrel. This will help to open up the valve. I will post pictures later when I get home. 

 

[spyde82]

Okay thank you, i Will change mine back

 

[spyde82]

Why would they go with a smaller spring and ad more hammer weight? Make no sense

 

[weatherby]

Why would they go with a smaller spring and ad more hammer weight? Make no sense

The old spring has got almost the exact same specs, only difference is that it is a little bit longer.

Wire diameter, outer diameter and number of coils is the exact same, only the pitch between coils is slightly larger.

 

[GQ]

Why would they go with a smaller spring and ad more hammer weight? Make no sense

The old spring has got almost the exact same specs, only difference is that it is a little bit longer.

Wire diameter, outer diameter and number of coils is the exact same, only the pitch between coils is slightly larger.

The new spring is 53 mm and the old original one is 57.

The 4 mm difference make more power to open the valve more for heavier slugs and pellets.

 

[SONG55]

spyde82,

This is the mod I did for VA spring. I cut off 3 rings. This will help hammer to open up the valve at higher reg pressure. 

 

[GQ]

spyde82,

This is the mod I did for VA spring. I cut off 3 rings. This will help hammer to open up the valve at higher reg pressure. 

The power plenum concept is mostly to shoot at the best speed with less regulator pressure .

 

[spyde82]

Would it not be easyer to replace the VA spring to a lighter one? Will it not give the same resoult? 

 

[buttles]

When I had my valve adjuster at the 4 ring or further out the fps didn't increase. I'm loathe to cut that spring as I feel at 4 it's doing little. It's also very noisy with the v2 spring if you don't have some damping.