Kalibrgun Cricket : Sudden velocity increase

[Airgnr_Ind]

Dear Mates,
I am unable to resolve the issue in my Gen I Cricket. Last month I had tuned it for JSB 25.39 Kings @ 920 Fps with Rgg pressure at 132 bar. Since then, would have fired 12 shots at two different occasions as I and taken the gun to a different location around 14 hours drive two weeks back.

Day before yesterday, I saw the guage on plenum showing 125 bar reg pressure instead of set 132/133 bar.
Therefore, to see the difference on fps, I just chronographed again yesterday. Now is the mystery....
First shot was at 935fps and second shot was at 974 fps.....
I had to loosen (anti cw) the HST, step by step, test... and finally by one half circle and 1/8 more, now the avg fps is 930 fps.

I refilled the rifle, the regulator pressure on guage is 125 bar.

Guage may have some issue....But, how did the velocity increase by itself. I am not able to understand .... I request if the Cricket owners/ experts can please share the feasible reason.

Warm Regards

 

[JaceSpace1369]

Dear Mates,
I am unable to resolve the issue in my Gen I Cricket. Last month I had tuned it for JSB 25.39 Kings @ 920 Fps with Rgg pressure at 132 bar. Since then, would have fired 12 shots at two different occasions as I and taken the gun to a different location around 14 hours drive two weeks back.

Day before yesterday, I saw the guage on plenum showing 125 bar reg pressure instead of set 132/133 bar.
Therefore, to see the difference on fps, I just chronographed again yesterday. Now is the mystery....
First shot was at 935fps and second shot was at 974 fps.....
I had to loosen (anti cw) the HST, step by step, test... and finally by one half circle and 1/8 more, now the avg fps is 930 fps.

I refilled the rifle, the regulator pressure on guage is 125 bar.

Guage may have some issue....But, how did the velocity increase by itself. I am not able to understand .... I request if the Cricket owners/ experts can please share the feasible reason.

Warm Regards

Sounds like your regulator settled at 123, instead of 132. Bear with me because my explanation may not be the most understandable. Your hammer is now applying more force than when it was with the regulator set 132b. Hence why reducing the hammer spring tension, fixed your issue.

 

[MushroomPsyche]

Dear Mates,
I am unable to resolve the issue in my Gen I Cricket. Last month I had tuned it for JSB 25.39 Kings @ 920 Fps with Rgg pressure at 132 bar. Since then, would have fired 12 shots at two different occasions as I and taken the gun to a different location around 14 hours drive two weeks back.

Day before yesterday, I saw the guage on plenum showing 125 bar reg pressure instead of set 132/133 bar.
Therefore, to see the difference on fps, I just chronographed again yesterday. Now is the mystery....
First shot was at 935fps and second shot was at 974 fps.....
I had to loosen (anti cw) the HST, step by step, test... and finally by one half circle and 1/8 more, now the avg fps is 930 fps.

I refilled the rifle, the regulator pressure on guage is 125 bar.

Guage may have some issue....But, how did the velocity increase by itself. I am not able to understand .... I request if the Cricket owners/ experts can please share the feasible reason.

Warm Regards

This will make sense if your hammer spring tension is set low relative to the 132 bar setting. At 132 bars, the gun is at partial valve lock, which means that at that particular hammer spring tension, the hammer is unable to completely open the valve. Lowering the regulator to 125 bars, the hammer is then able to open the valve more fully increasing the dwell time.

 

[Airgnr_Ind]

Sounds like your regulator settled at 123, instead of 132. Bear with me because my explanation may not be the most understandable. Your hammer is now applying more force than when it was with the regulator set 132b. Hence why reducing the hammer spring tension, fixed your issue.

Thanks sir.... sounds convincing.

 

[Airgnr_Ind]

This will make sense if your hammer spring tension is set low relative to the 132 bar setting. At 132 bars, the gun is at partial valve lock, which means that at that particular hammer spring tension, the hammer is unable to completely open the valve. Lowering the regulator to 125 bars, the hammer is then able to open the valve more fully increasing the dwell time.

Thanks sir. This can be the reason. That ways Rifle seems more efficient now. Will note the shot count now.

 

[MushroomPsyche]

Thanks sir. This can be the reason. That ways Rifle seems more efficient now. Will note the shot count now.

In your rifle's case, it's actually going to use more air at the lower reg pressure as the dwell time has increased. The upside though is I think the consistency should improve a little. In any case though, you should really be setting the regulator pressure for a projectile you want to shoot and at the power you want to shoot it at, and THEN, set the hammer spring tension to achieve consistency and efficiency. It about the balance between reg pressure and hammer spring tension.

 

[Airgnr_Ind]

In your rifle's case, it's actually going to use more air at the lower reg pressure as the dwell time has increased. The upside though is I think the consistency should improve a little. In any case though, you should really be setting the regulator pressure for a projectile you want to shoot and at the power you want to shoot it at, and THEN, set the hammer spring tension to achieve consistency and efficiency. It about the balance between reg pressure and hammer spring tension.

Thanks sir for the input.