I don't think higher regulator pressure and the associated higher hammer spring force should hurt the gun but I have found it harder to get a gun to do something that it wasn't really intended to do. My P35-25 shoots JSB 34 grain pellets the best but cannot consistently get them going 800 fps. I have achieved it a few times but the hammer spring is weak so the regulator pressure cannot exceed about 150 bar or the hammer won't open the valve. Shimming the hammer spring let me get a few more fps but it seemed like every time I wanted to shoot the gun a little the velocity had fallen under 700 fps because the hammer spring wasn't putting out enough force because the temperature of the air had risen making the valve a little harder to open or something. So I would lower the regulator and get it working again and then have to repeat it later. So I recent just backed the regulator down about 1/4 turn which allowed me to remove all the shims from the hammer spring. Velocity is only about 730 but the gun shoots fine and I'm hoping it will the next time I pull it out. The hammer spring is not at maximum but is close. (I tried a reduced size poppet this week but it didn't work for me, velocity did not go up with a 0.5mm reduction in size apparently due to a little shape difference. When I reshaped the reduced diameter poppet it wouldn't seal and I went back to the OEM poppet. I may still mess with that some more)
If all you have to do is increase the regulator and the hammer spring and the gun cooperates, I think you are within it's design parameters and it should work fine. To me, doing this to get 800-900 fps from a pellet the gun likes is a good and reasonable thing to do. Doing it because your buddies gun makes 50 fpe and you think yours should isn't something I would support. I want enough velocity to have good accuracy and trajectory but the power can be whatever it is.
Another parameter is how much space there is between the fill pressure and the regulator pressure. My Avenger arrived with the regulator turned up to 2900 psi or something like that and I immediately degassed the gun and turned it down. I was hand pumping when I got it and 300 bar is a lot of work to hand pump a gun to. I use a compressor and a bottle now but the bottle only goes to 300 bar so the gun never really gets filled to that unless I fill directly from the compressor. My usable shots are only down to the regulator setting or a little below. So with the original setting ~4000-2900 psi. I now have it at about 2200 psi so I have 700 psi more air in each fill to use. One of the neat things about my Caiman X is it will send 18 grain Baracudas 900 fps with a 100 bar reg pressure. It also fills to 300 bar. So it gives me a lot of shots. I've tried slugs in it and they shoot reasonably well and it can get them going fast with more regulator pressure but the barrel is choked and accuracy is not as good as pellets at any tune I've tried. So I'll probably retune it for pellets soon.
I think it's a good goal to find what your gun wants to shoot and then tune it to do it as accurately as possible. I think trying to make a gun shoot a particular pellet well or at a particular power level is kind of fighting with the gun and you might not like the outcome as much as you think you will.
If all you have to do is increase the regulator and the hammer spring and the gun cooperates, I think you are within it's design parameters and it should work fine. To me, doing this to get 800-900 fps from a pellet the gun likes is a good and reasonable thing to do. Doing it because your buddies gun makes 50 fpe and you think yours should isn't something I would support. I want enough velocity to have good accuracy and trajectory but the power can be whatever it is.
Another parameter is how much space there is between the fill pressure and the regulator pressure. My Avenger arrived with the regulator turned up to 2900 psi or something like that and I immediately degassed the gun and turned it down. I was hand pumping when I got it and 300 bar is a lot of work to hand pump a gun to. I use a compressor and a bottle now but the bottle only goes to 300 bar so the gun never really gets filled to that unless I fill directly from the compressor. My usable shots are only down to the regulator setting or a little below. So with the original setting ~4000-2900 psi. I now have it at about 2200 psi so I have 700 psi more air in each fill to use. One of the neat things about my Caiman X is it will send 18 grain Baracudas 900 fps with a 100 bar reg pressure. It also fills to 300 bar. So it gives me a lot of shots. I've tried slugs in it and they shoot reasonably well and it can get them going fast with more regulator pressure but the barrel is choked and accuracy is not as good as pellets at any tune I've tried. So I'll probably retune it for pellets soon.
I think it's a good goal to find what your gun wants to shoot and then tune it to do it as accurately as possible. I think trying to make a gun shoot a particular pellet well or at a particular power level is kind of fighting with the gun and you might not like the outcome as much as you think you will.
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