Fwb-601 velocity issues

[Bob85]

Hi all,

I have a fwb-601 air rifle, and i have some pellet velocity issues. It produces 184,4 meters/second with the 0,475 grams jsb exact rs pellet, and i need to downgrade it to 178-180 meters/seconds to fit the hunter field target rules in my country.
There is a hammering spring which is adjustable and this may be the solving of the problem, but I don't know how much adjust it needs. (There is a video in youtube, where mentioned: https://youtu.be/KulIF-HsoX 12:37) I only know for loosening I need to turn the screw counter clockwise, but don't know how much. What happens if I turn too much out, or in?
Any leads is appreciated.

[Th.]

I would chose a heavier pellet. It bring’s down the velocity and it will be less effected by the wind.

[Bob85]

I would chose a heavier pellet. It bring’s down the velocity and it will be less effected by the wind.

That is the other way which i will try but this is not only about the velocity, but the energy what is 7,5 joules ( the law limit) and there is a little tolerance in it.

[Th.]

You can calculate it.
https://www.calculatorsoup.com/calculat ... inetic.php

[spektr]

unless you adjust the powerplant, the pellet weight will only affect velocity, and total energy will remain where it is now.

[Bob85]

unless you adjust the powerplant, the pellet weight will only affect velocity, and total energy will remain where it is now.

That is the question, how to do it. Is's ok to turn the hammering screw but how much for not to make another problem.

[spektr]

Turning the hammering screw is not going to work. This is an SSP gun, not a Pcp gun. 100% of all air compressed is discharged each shot. There is no regulator or reservoir feeding the gun that would make the gun susceptible to hammer spring adjustment to change shot volume. Shot volume is fixed by the powerplant stroke X diameter. If you need to change the velocity, you modulate the pellet weight OR get into the powerplant and start making very tiny adjustments to remove shims installed at the factory to regulate stroke distance to get the velocity desired with the test pellet.

[Bob85]

Turning the hammering screw is not going to work. This is an SSP gun, not a Pcp gun. 100% of all air compressed is discharged each shot. There is no regulator or reservoir feeding the gun that would make the gun susceptible to hammer spring adjustment to change shot volume. Shot volume is fixed by the powerplant stroke X diameter. If you need to change the velocity, you modulate the pellet weight OR get into the powerplant and start making very tiny adjustments to remove shims installed at the factory to regulate stroke distance to get the velocity desired with the test pellet.

Could you please suggest a pellet weight which is enough heavy to reach the desired energy? I'm a bit noob for this.