Other Newbie artemis p15

I agree with Neu, the OP needs to give us some data for us to be able to help. About $20 will get you a very serviceable chronograph. Get one, fill the gun to 150 bar or so and shoot any 177 pellet you have through it until the velocity falls. Note the pressure. You reg is set a little above that pressure. Tell me what weight pellet you shot, the velocity it went before it went down and the pressure at which it went down. Lastly tell me what you want the gun to do differently. If you will do these things I or others will help you. If you do not tell us these things we can't do much.

Thanks for that information. Do you know what the pressure was at on the gauge when the velocity was maybe 20 fps lower than before? That would be very helpful to see where your regulator is set.

But regardless, the first thing to try is increasing the hammer spring and see what happens to velocity. There is a screw on the back of the air tube that lets you adjust how hard the hammer hits the valve. Try turning it clockwise 1 half turn and record the velocity. If it goes up try another half turn. Keep increasing until it stops going up. You probably don't want to stop at the highest velocity you get. Usually you turn the banner screw enough to reduce velocity from the peak by 3 to 5 percent. But it won't break the gun to stay at the peak.

If the velocity from adjusting the hammer spring is not high enough you can raise the regulator setpoint. But that is harder to do. But I can tell you how.